In the carpentry world there is a certain respect to anyone who can do things based on knowing the terms. For instance if a carpenter is asking for something rough sawn or in the rough, he wants to know about a product that is not surfaced. Now we won’t be dealing with that particular term in this section but we will be dealing with many other abbreviations and terms. Let’s start with abbreviations.

The more common primary terms are words you will come across quite often and you’ll need to know. The secondary terms are terms are words that you may or may not hear but will help you understand what someone is talking about when telling you, the expert, how they are building their deck. Know these primary terms and understand the secondary ones. The abbreviations will usually be on written documents that you will see. For a more exhaustive list of terms open the tabs below.

Lumber Glossary Term Definition
A-Frame Two wooden or metal uprights mounted in the shape of the letter “A” to support lead blocks at the upper end.
Above-ground Biomass The above ground portion of a tree, excluding the root system.
Abney Level Hand-held clinometers that are used to measure slope in percent.
Abrasives A material that is used to shape or finish a work piece through rubbing which leads to the work piece being worn away.
Absolute Humidity The weight of water vapor per unit of air; usually expressed as grains/cu. ft.
Absorption The gain of free water by the cell cavities.
Access The means of gaining entry to timber on a tract or logging chance.
Accumulating Sheer Shearhead on a feller-buncher that is capable of accumulating and holding two or more cut stems.
Across The Grain Generally perpendicular to the grain direction.
Actual Dimensions The exact measurements of a piece of lumber. (i.e. – a 2×4 (nominal dimensions) is actually 1 ½ inches thick by 3 ½ inches wide.)
AD (Air-Dried) Lumber which has been air dried.
ADF A term used to define a condition upon which payment of an invoice may be made.
ADI After date of Invoice.
Adherent A material that is held to another material by an adhesive.
Adhesion A substance in which two surfaces are held together by
inter-facial forces, which may consist of valence forces or interlocking
action or both.
Adhesive A substance capable of bonding material together by surface attachment.

  • Assembly Adhesive – An adhesive that can be used for bonding parts
    together, such as in the manufacture of a boat, airplane, and furniture.
  • Cold-Setting Adhesive – An adhesive that sets at a temperature below 68 degrees Fahrenheit (20 degrees Celsius)
  • Construction Adhesive – Any adhesive used to assemble primary
    building materials into components during building construction; most
    commonly applied to elastomeric-based adhesives.
  • Contract Adhesive – An adhesive that is apparently dry to the touch
    and that will adhere to itself instantaneously upon contact; also
    called contact bond adhesive.
  • Gap-Filling Adhesive – An adhesive capable of forming and maintaining a bond between surfaces that are not close fitting.
  • Hot-Melt Adhesive – An adhesive that is applied in a molten state and forms a bond upon cooling to a solid state.
  • Hot-Setting Adhesive – An adhesive that requires a temperature at or above 212 degrees F.
  • Room Temperature Curing Adhesive – An adhesive that sets in the
    temperature range of 68 to 86 degrees F, in accordance with the limits
    for Standard Room Temperature specified in the Standard Methods of
    Conditioning Plastics and Electrical Insulting Materials for Testing.
  • Solvent Adhesive – An adhesive having a volatile organic liquid as a vehicle.
  • Structural Adhesive – A bonding agent used for transferring
    required loads between adherents exposed to service environments typical
    for the structure involved.
Admiralty Shackle A heavy shackle at the tail end of the tree that connects the skyline to the sub line (guy line extension).
Adult Wood Wood produced after cambial cells have attained maximum dimensions.
Advanced Decay An older stage of decay readily recognized as wood
that has become punky, soft, spongy, stringy, rinkshaked, pitted, or
Adverse Grade In highway transport, uphill haul that requires
trucks to use lower gears; a gradient that slopes upward in the
direction of loaded log truck travel.
Aerial Logging Yarding system employing aerial lift of logs, such as balloons or helicopters.
Afforestation Establishment of forest crops through artificial
methods, such as planting or sowing on land where trees have never
African Blackwood
African Blackwood
  • Dark purple-brown with black streaks
  • Usually straight grained
  • Extremely fine and even texture
  • Exceptionally heavy and dense
  • Difficult to work with
  • Pre-boring is required
  • Used for woodwind instruments, ornamental work, carved figures, walking sticks, knife handles and inlay work
African Mahogany
African Mahogany
  • Heartwood varies from light to deep reddish-brown
  • Straight to interlocked grain
  • Moderately coarse textured
  • Widely used for furniture and cabinet making, interior joinery, boat building and decorative work
African Padauk
African Padauk
  • Vivid blood red heartwood to dark purple-brown
  • Straight to interlocked grain
  • Excellent strength properties
  • Medium resistance to shock loads and stiffness
  • Used for fancy turnery, tool and knife handles, paddles, oars, agricultural implements, and heavy-duty flooring
African Walnut
  • Bronze-Orange heartwood
  • Interlocked grain
  • Fine texture
  • Lustrous
  • Medium crushing strength
  • Low bending strength
  • Resistance to shock loads
  • Very low stiffness
  • Moderate bending classification
  • Works well with hand and machine tools
  • Tends to split when nailed
  • Used for furniture, cabinets, paneling, gun stocks, domestic flooring, and billiard tables.
After Date of Invoice A term used to define a condition of sale; cash
discounts are often allowed for payment within a specified period “after
date of invoice.”
After Deducting Freight A term used to define a condition upon with payment of an invoice may be made.
Against The Grain A reference to the cutting direction; as in
planing a board surface, such that splitting ahead of the cutter follows
the grain direction downward into the wood below the projected cutting
surface. Also, generally perpendicular to the grain direction, across
the grain.
Age Mean age of the trees comprising a crop, forest, or stand. In
forests, the mean age of dominant (and sometimes co-dominant) trees is
taken. The plantation age is generally taken from the year the
plantation was begun without adding the age of the nursery stock.
Age Class One of the intervals, commonly 10 or 20 years, into which
the age range of tree crops is divided for classification or use. Also
pertains to the trees included in such an interval. (i.e. trees ranging
in age from 21 to 40 years fall into a 30-year ago class; 30 designates
the midpoint of the 20-year interval from 21 to 40 years.)
Air Cleaner (Air Polisher) A machine designed to filter fine dust
from the air in a workshop. A blower moves air past a series of filters
to capture the airborne dust.
Air Compressor A compressor that takes in air at atmospheric pressure and delivers it as a higher pressure.
Air-Dried Lumber Lumber that was dried, usually outside, to
equilibrium moisture content with the air it was exposed to. Any lumber
below 30% MC is classified as air dried. Construction grade is around
19% MC. Moisture content of air-dried wood fiber depends on length of
drying period, relative humidity, and temperature. It’s also referred to
as air seasoned.
Air Hose A hose that carries air under pressure.
  • Dull reddish brown with darker lines
  • Low bending classification
  • Low bending strength
  • Resistant to shock loads
  • Very low stiffness
  • Medium crushing strength
  • Low cutting resistance
  • Nails and screws satisfactorily
  • Glues well
  • Used for brooms, hat blocks, toys, wooden clog soles, veneers
All-Aged Forest or stand containing trees of almost all age classes up to and including trees of harvestable age.
All Widths and Lengths A term used indicating that all widths and
lengths of a specified thickness of lumber may be included in a
Allen Head A screw head with a recess requiring a hexagon shaped
key, used mainly on machinery. These may be in metric or SAE sizes.
Allowable Cut Volume of timber that may be harvested during a given period of time to maintain sustained production.
Allowable-Cut Effect (A.C.E) Allocation of anticipated future
forest timber yields to the present allowable cut; this is employed to
increase current harvest levels, especially when constrained by even
flow by spreading anticipated future growth over all the years in the
Allowable Property The value of a property normally published for
design used. Allowable properties are identified with grade descriptions
and standards, reflect the orthotropic structure of wood, and
anticipate certain end uses.
Along the Grain Generally paralleled to the grain direction.
Alternate An alternating set of teeth on a saw blade with a left-right sequence.
Alternate Top Bevel with Raker (ATB/R) A design for a circular saw
blade where four alternately beveled teeth are followed by a raker tooth
to remove debris from the cut.
Ambrosia Maple
Ambrosia Maple
  • The ambrosia beetle causes the wormy pattern in this soft maple
  • Beautiful brown and gray stripes with small worm holes
  • Medium bending and crushing strength
  • Used for furniture and flooring
American Lumber Standard The American Softwood Lumber Standards
establishes standard sizes and requirements for the development and
coordination of lumber grades of various species, the assignment of
design values when called for, and the preparation of grading rules
applicable to each species.
American Tree Farm System (ATFS) A program of the American Forest
Foundations Center for Family Forests is the oldest of forest
certification programs and was established in 1941. The ATFS focuses its
program on private family forest landowners in the United States.
Anchor Piece of equipment that holds something in place.
i.e. – a clamp is a type of anchor.
Anchor Cable A line used to tie down a yarded to prevent tipping on heavy pull.
Anchor Log Concrete, metal or wooden bars buried in the earth to hold a guy rope. This is also called a deadman.
  • Light mahogany color to reddish-brown
  • Straight grained, occasionally interlocked with ripple marks, producing Fiddleback figure.
  • Medium bending and crushing strength
  • Low stiffness
  • Sanding is required for smoother finish
  • Pre-boring is necessary for nailing
  • Used for boat and ship decking, light construction, flooring and rafters, furniture, and turnery.
  • Heartwood is cream colored to tan with a pinkish tinge
  • Usually straight grained, sometimes wavy
  • Medium to coarse texture
  • Medium bending strength
  • Used for furniture, cabinet wood, general utility and interior purposes
Anisotropic Shows different properties when measured along a different axes.
Annual Allowable Harvest Quantity of timber scheduled to be removed from a particular management unit in one year.
Annual Growth Rings The layer of growth that a tree puts on in one
year. The annual growth rings can be seen in the end grain of lumber.
Applied Carving A background which is worked separately and then applied, rather than being worked in place.
Apron A frame around the base of a table to which the top and legs are fastened.
Arbor A shaft, driven by the tools motor that turns blades or other cutting tools.
Arch Supporting device mounted on or towed behind or a skidding
vehicle. This is used to lift one end of a log(s) to reduce sliding
resistance and/or transfer the weight.
Area Regulation Method of controlling the annual or periodic
acreage harvested from a forest, despite fluctuations in fiber-yield
volumes. This leads to a managed forest.
Area Salvage Timber sales in which the USDA Forest Service sells
dead timber within a given area. Usually covers more than an operating
season and requires the operator to return annually to remove any dead
timber present.
  • Grey-brown heartwood
  • Generally straight grained and coarse
  • Even textured
  • Variable bending properties
  • Good strength, elasticity, toughness, stiffness, and hardness qualities.
  • Excellent shock resistance
  • Pre-boring is necessary when nailing
  • Used for all types of sport equipment, bats, cues, oars, handles, church pews, cabinets, and decorative veneers.
Assembly Time The time elapsed between spreading adhesive on
surfaces to be joined and application of pressure to the joint. Open
assembly time is from the beginning of spreading to joint closure.
Closed assembly time is from joint closure to application of full
Attached Deck A deck with one or more sides supported by a ledger and attached to a house.
Association of American Railroads (AAR) A trade association based in Washington, D.C. representing the nations Class I Railroads. The AAR represents the industry in the broad fields of Law, Public Affairs, Legislation, Economics and Finance, Research and Testing, Transportation, Safety, Engineering, Freight Claim and Prevention and Car service.
Auger Various hand tools, typically that have a threaded shank and cross handle, used for boring holes in ice or wood.
Australian Cypress
Australian Cypress
  • Mostly golden colored
  • Closed and tight grain
  • Very durable
  • Used for flooring, feature finishes, and cabinets
Awl A pointed instrument that looks like an ice pick, useful for marking positions when laying out a project.
AWLS A term used indicating that all widths and lengths of a specified thickness of lumber may be included in a shipment.
AW&L A term used indicating that “all widths and lengths” of a specified thickness of lumber may be included in a shipment.
Lumber Glossary Term Definition
B&S Beams and Stringers
B/L Bill of Lading – A written document issued by a carrier serving as a
receipt of goods and as a contract to deliver goods to a specified
Backcut The final cut in felling a tree, made on the opposite side of the direction of fall.
Backfire A blaze set in front of an advancing forest fire in an effort to check the wildfire by cutting off its fuel supply.
Back Saw A short rectangular saw with fine teeth and a rigid
“spine” along the top of the blade. A back saw is used for fine joinery
work such as cutting dovetail joints.
Balanced Construction The symmetrical construction of plywood or
other composites having matching layers on both sides of the central
plane so that changes in moisture content will not cause warp.
Baluster One of a series of vertical supports used between posts of a railing. This is also called a spindle.
Band Saw A saw with a looped blade running around two or three
wheels. This is used with narrow blades for cutting freehand shapes, or
with wider blades and a guide for re-sawing material.
Band Strength The ability of saw blade to resist deflection determined by width & thickness (AKA beam strength).
Bare Root seedling; tree seedling grown in a nursery bed. When
large enough for transplanting, the seedling is lifted from the nursery
bed, and the dirt is removed from the roots before packaging.
Bark The outermost, protective layer of a tree composed of dead cork and other various elements.
Bark Beetle Small, cylindrical beetle of the family Scolytidae, the
adult of which bores into and beneath the bark of various trees for the
purpose of egg laying.
Bark Pocket An opening between annual growth rings that contains
bark. Bark pockets appear as dark streaks on radial surfaces and as
rounded areas on tangential surfaces.
Barker A machine used to remove bark from pulpwood.
Barking Drum A large drum in which logs or billets are tumbled by
mechanical rotation, the back being removed by abrasive action.
Barking Iron A tool with a curved, narrow-shaped blade used in removing bark by hand.
Bark Residue Refers to the bark removed from a log and also to
portions of wood and foreign matter such a grit, sand, or stones that
may be imbedded in the bark.
Basal Area Cross sectional area of a tree, in square feet, measured
at breast height. This is used as a method of measuring the volume of timber in
a given stand.
  • Creamy white to pale pink color
  • Straight grained and fine
  • Even texture
  • Poor steam bending classification
  • Very low strength properties
  • Low resistance
  • Used for hand carvings, piano keys, beehives, picture framing, toys, veneers, and boxes
Bastard Grain Annual rings on an angle at or near 45 degrees to the wide face of a piece of lumber.
Bastard Sawn Lumber in which the annual rings make angles of 30 to 60 degrees with the surface of the piece.
Bay The space between two timber bents.
BD Board
BDFT Board foot
BDL Bundle
Bead A semicircular piece of molding.
Beam A main horizontal member in a buildings frame. Beams usually are supported by posts.
Beams and Stringers Large pieces (nominal dimensions, 5” and
thicker, width more than 2” greater than thickness) of rectangular cross
section graded with respect to their strength in bending when loaded on
the narrow face.
  • Reddish-brown
  • Straight grained
  • Fine, even texture
  • Excellent wood bending properties
  • High crushing strength
  • Medium stiffness
  • Medium resistance to shock loads
  • Good nailing and gluing properties
  • Excellent for turnery
  • Used for cabinetmaking, flooring, turnery, handles, veneers
Beetle A heavy wooden mallet or maul used when material would be damaged by a sledge hammer.
Belt Sander A machine used to sand down wood or other materials for
finishing purposes. It has an electrical motor that turns a pair of
drums on which a seamless loop of sand paper is mounted; it can be handheld
or stationary.
Bench Dog A metal part of a wooden peg that fits into a hole in a
workbench that is used to hold a work piece in place. The peg can be
round or square and sometimes is fitted with special springs to hold
them in place.
Beneficiation A process used to upgrade chips, making them more
acceptable for paper and pulp manufacture. Beneficiation is accomplished
when acceptable chips are separated from unacceptable ship.
Bent A structural section of a frame which is composed of a line of
vertical posts and the horizontal timbers that connect them.
Bent Design The artistic, yet functional pattern of timbers creating the bend.
Better A term usually used to indicate that a lumber shipment
contains a percentage of pieces that are of a higher grade than the
lowest grade stated. (i.e. No. 2 & BTR would contain pieces of No. 2 grade and some that are of a higher grade.)
BEV Bevel
Bevel Cut An angled cut through a board.
Bevel Gauge Also known as a T-bevel, the bevel gauge is a flat
piece of metal attached to a handle with a wing nut that allows the
metal piece to be set at any angle to the handle. Its used primarily to
mark angles when copying them from  a plan or piece of the deck to
another piece.
BH Boxed Heart
  • Yellow sapwood
  • Reddish-brown heartwood
  • Straight, close grained
  • Fine and even texture
  • High bending strength, crushing strength and resistance to shock loads
  • Uniform, dense surface
  • Free from large groups of pores
  • Used for furniture, flooring, turnery, cabinets, and marquetry
Birds-Eye Figure A figure composed of many small “BB” size rounded
areas, resembling a bird’s eye. The figuring is most common on plain and
rotary sawn lumber and is generally found on maple, along with a few
other species.
Bi-metal Blade Band saw blade composed of two types of welded alloy steel.
Bind To get a saw stuck when bucking or felling a tree and the
sides of the cut pinch in; wedges are used to alleviate the situation.
Binder Chain or wire rope used to bind logs. This is also known as a chain hook.
Biomass Total woody material in a forest. This refers to both
merchantable material and material left following a conventional logging
Biomass Harvesting Harvesting of all material including limbs,
tops, and unmerchantable stem and stumps, usually for energy wood.
Biscuit Joint A butt joint that is reinforced with a football
shaped “biscuit”. The biscuits are usually made from compressed pieces
of wood, most commonly birch. When a biscuit comes in contact with glue
in the joint, it swells creating a tighter joint.
Blade Stabilizers Metal disks approximately 3 ½” in diameter that
go on each side of a saw blade to minimize flexing and rim vibrations.
Blank A roughly cut wooden block intended for further shaping or finishing.
Blister An elevation of the surface of an adherent, somewhat resembling in shape a blister on human skin.
Blemish A defect or anything that marks the appearance of wood.
Block Plane A small plane used to finish off rough edges of a deck.
  • Heartwood varies from gray-red to deep rich red
  • Straight to variable grain
  • Fine and smooth texture
  • High bending and crushing strength
  • Used for cabinets, furniture, decorative inlay, and marquetry work
Bloom Crystals formed on the surface of treated wood by exudation and evaporation of the solvent in preservative solutions.
Blow Usually in plywood and particleboard, the development of steam
pockets during hot pressing of the panel, resulting in an internal
separation or rupture when pressure is released.
Blue Board A weather resistant, plaster-based drywell.
Blue-Stain Discoloration in the sapwood of pine. At one time, this
was thought to be a serious defect but now it is used as high-quality
interior finish.
Blue-Stain Fungus The most common form of fungal stain occurring in
sapwood. Conifers are most susceptible but it may also occur in
light-colored heartwood other or perishable timbers. It commonly
develops in dead trees, logs, lumber, and other wood products until the
wood is dry. It also reduces the grade of wood, but does not significantly
reduce the strength. Some blue-stain lumber is highly valued for
specialty products.
BM Board Measure
Board Foot The basic unit of measurement for lumber. (i.e. – One board
foot is equal to a 1-inch board, 12 inches in width and 1 foot in
length. A 10-foot long, 12-inch wide and 1-inch thick piece would
contain 10 board feet. When calculating board feet, nominal sizes are
Board Measure Is used to indicate that a ‘board foot’ is the unit of measure.
Boards Lumber two-inches or more wide that is nominally less than
two-inches thick. Boards less than six-inches wide are also called
Bole A tree stem that has roughly grown to a substantial thickness;
capable of yielding large poles, saw timber, or veneer logs.
Bolt A short section of a tree mark.
Bookmatch A term in sawing or veneering, where successive pieces of
boards or veneer, from a flitch or a log, are arranged side by side. A
properly done bookmatch will resemble a mirror image of the opposite
side. Also known as butterflied, mirrors, and sisters.
Bond The union of materials by adhesives.
Bond Failure Rupture of adhesive bond.
Bond Strength The unit load applied in tension, compression,
flexure, peel impact, cleavage, and/or shear required to break an
adhesive assembly, with failure occurring in or near the plane of the
Bone-Dry Ton Wood pulp or residue that weigh 2,000 pounds at zero percent moisture content. This is also known as an over-dry ton.
Bondline The layer of adhesive that attaches two adherents.
Bore A hole for the arbor in a circular saw blade.
Bottom Rail The horizontal member, installed on edge, attached to
the bottom of the balusters, as well as the post. The bottom rail is not
required if the balusters extend to and are attached to the Rim Joist.
Bound Water Water found within the cell wall of wood.
Boule A log live sawn and kept together in the order of sawing.
Bow A defective piece of lumber that has warped along its length.
Box Beam A built-up beam with solid wood flanges and plywood or wood-based panel product webs.
Box Heart The term used when the pith falls entirely within the four faces of a piece of wood anywhere in its length.
Box Joint A corner joint made up of interlocking “fingers”.
Box Lumber Factory lumber, may be of any thickness, 4/4 and thicker and is graded for box cutting value.
Box Shook Produced by resawing standard S2S lumber; is cut to size
for box manufacture but not yet assembled may be manufactured in many
sizes to meet each individual buyer’s requirements.
Boxed Heart Used when the pith falls entirely within the four faces anywhere in the length of a piece.
Braces Smaller timbers placed diagonally between posts and girts (plates) to make a structure more rigid.
Brace and Bit A hand drill with a crank shaped handle with a flat
knob on the end, special auger bits with a square tapered shank fit into
a two jaw chuck. This is an ancient system but still works well for
jobs done by hand.
Bracing Structural supports placed between posts and beams or joists to provide stability to the structure.
Brad A small finishing nail up to 1” long.
Brad Point Bit Similar to a twist drill but with a flat bottom and sharp point.
Brand A log mark used to identify logs.
Branding Ax An ax used to stamp brands into logs.
Branding Iron A tool used for burning a logo or name on to wood; electric or flame heated.
Brashness Brittleness in wood, characterized by abrupt failure
rather than splintering. Causes include reaction wood, juvenile wood,
compression failure, high temperature, and extremes of growth rate.
Brazilian Cherry
Brazilian Cherry
  • Heartwood is salmon red to orange-brown with dark brown streaks
  • Usually interlocked grain
  • Medium to coarse texture
  • Very strong, hard, and tough
  • Good bending characteristics
  • High shock resistance
  • Moderately difficult to work with
  • High density
  • Used for furniture, turning, tool handles, sporting goods, flooring, and joinery
Break A piece of equipment that bends metal sheeting into perfect angles.
Breaking Radius The limiting radius of curvature to which wood or plywood can be bent without breaking.
Bridging Boards placed perpendicularly between joists to stiffen
the joists. Frequently, bridging is made from the same dimensions lumber
as the joists.
Bright Term used to indicate that lumber is free from discoloration.
Bright Sapwood/No Defect Bright sapwood that is permitted in each piece of any amount.
BSND Bright Sapwood No Defect
BTR Better
  • Medium red-brown color
  • Straight or interlocked grain
  • Moderately coarse texture, but even
  • Low steam bending qualities
  • Used for turnery, knife handles, decorative veneers for cabinets and paneling
Buglehead Screw A screw with a curved taper between the head and
shank or threads so it doesn’t tear the wood when screwed down flush
with the surface.
Building Code A set of regulations governing construction in a
particular political subdivision, such as a city or county. The building
code spells out requirements pertaining to such criteria as grades,
lumber strength, spans and values.
Built-Up Timbers An assembly made by joining layers of lumber
together with mechanical fastening so that the grain of all laminations
is essentially parallel.
Bullnose The process of rounding an edge of a board used for seating, shelving, stadium seating steps, etc.
Burl Bulges and irregular growths that form on the trunks and roots
of trees. Burls are highly sought after for the incredible veneer they
Burr A raised ridge of metal used on a scraper to remove wood.
Butt Diameter The larger cross-sectional measurement of a log, at the end toward the original base of the tree.
Butt Joint A woodworking joint where the edges of two boards are placed against each other.
Buttress A ridge of wood developed in the angle between a lateral
root and the butt of a tree, which may be extended up the stem to a
considerable height.
  • Medium dark brown heartwood
  • Straight grained
  • Low wood bending classification
  • Works easily with hand and power tools
  • Nails, screws and glues well
  • Used for high-class joinery, interior trim for boats, furniture, boxes, and crates
Lumber Glossary Term Definition
C&F Cost and Freight
Caliper Instrument for determining log and tree diameters by
measuring their rectangular projection on a straight graduated rule via
two arms, one of them sliding along at right angles to the rule itself.
The optical caliper determines upper, out-of-reach diameters through an
optical system incorporating two parallel lines of sight separated by a
variable baseline.
Cambium The live, actively growing layer of a tree. The cambium is
one cell thick and resides between the phloem and sapwood. It repeatedly
divides itself to form new wood which causes the tree to expand and
grow. It is the layer that becomes either bark or wood and lays dormant
during winter.
Canadian Standards Association (CSA) A non-profit organization that has developed over 2,000 different standards for a variety of industries.
  • Heartwood varies from pale-yellow-brown to pale olive-brown streaks
  • Usually straight and regular grain
  • Medium density
  • Used for pattern making, musical instruments, cabinets, interior trim for boats, toys and doors
Canopy A continuous cover of branches and foliage formed collectively by adjacent tree crowns.
Cantilever The allowable overhang past the joists or rim joists.
Cant A log that has been debarked and sawn square.
Cap Rail The top horizontal piece of a railing placed to give it a finished appearance.
Carcase The body of a piece of furniture with a box like shape.
Carbide Tipped Extremely hard steel pieces with sharp cutting edges
fastened to cutting tools such as saw blades, and router bits.
Carload A railroad car loaded to meet railed minimum weight
requirements for carload rates. The volume in a carload may vary,
depending upon the type of lumber loaded and the size of the car.
Card Scraper A flat blade with a burred edge used for smoothing.
Carpenter’s Pencil Rectangular shaped pencil, about 1/4”x ½”, with a 1/16” x 3/16” lead.
Carriage Bolt A bolt with a rounded head that is pulled down onto the
surface of the wood as the nut is tightened. It’s used to hold structural
members together, as the rounded head gives a finished look to the bolt.
Bolts should be checked annually and tightened when necessary.
Case Hardening A defect in lumber caused when a board is dried too
fast, or improperly. The outer layers in a case hardened board are
compressed while the inner layers are in tension.
Casing Usually run to pattern and is widely used for interior trim.
Cat’s Paw A person used by another as a dupe or a tool.
Catalyst A substance that initiates or changes the rate of chemical reaction but is not consumed or changed by the reaction.
Caul Veneering A method where the veneers are cut square, taped
together and laid as a single sheet without preliminary dampening.
Caulking Seam A machined groove or depression worked in the wood.
It provides a weather resistant joint when filled with caulking material
and fitted with an adjoining piece.
CB Center Beaded
Cedar Any spreading evergreen conifer of the genus Cedrus bears tufts
of small cones and needles. In full cedar wood, the fragrant durable
wood of any cedar tree. Cedar lumber provides one of the best choices
for deck construction, although more expensive than the cheaper options,
it will last much longer because of its natural decay resistant and
insect repellant properties.
Ceiling A lumber pattern featuring a center and edge V and/or bead.
Cell The smallest, microscopic structure in wood.
Cellulose The carbohydrate that is the principal constituent of wood and forms the framework of the wood cells.
Cement A powder that serves as a binding element in concrete and mortar. Also, it is an adhesive.
Center Beaded A patterned lumber shaped to form a narrow half-circle along the center of its length.
Center Match (CM) Lumber that has been worked with a tongue exactly
in the center on one edge of each piece and a groove on the opposite
edge to provide a close tongue-and-groove joint by fitting two pieces
Center V (CV) Patterned lumber shaped to form an angled groove along the center of its length.
Center-to-Center Spacing The spacing between structural members
determined by measuring from the center of one to the center of the
next. (i.e. 16-inches o.c.)
Chain Saw A saw that is powered by an electric motor, gasoline, or
hydraulics; cutting elements are on an endless chain similar to a
bicycle chain.
Chalk Line An enclosed reel of string coated with colored chalk and
used to mark straight lines by pulling the string taut and snapping the
string, leaving a line of chalk marking a line. Commonly used in deck
building to mark the edge of decking so that all decking boards can be
cut off flush with each other.
Chamfer A bevel or slope created by slicing off the square edge or
end of a piece of wood or other material (usually 45 degrees); a
decorative edging or relief made at the timber’s corner.
Check A lumber defect caused by uneven shrinking of the wood during
drying. A checked board has splits that develop lengthwise across the
growth rings.
Check Scaler A person who rescales logs in order to detect errors in the initial scaling.
Chemical Pulping A process in which wood fibers are separated by
removing the lignin and other wood components through the use of
Chemical Thinning Any thinning in which the unwanted trees are killed
by chemical poisoning; band or frill girdling may be done at the same
  • Heartwood varies from rich red to reddish-brown
  • Fine, straight, close grain
  • Smooth texture
  • Good wood bending properties
  • Low stiffness
  • Medium strength and resistance to shock loads
  • Takes an excellent polish
  • Used for tobacco pipes, musical instruments, furniture, cabinets, boat interiors, decorative veneers, and wall paneling
Chip A small piece of wood used to make pulp. Chips are made either
from wood waste in a sawmill, pulpwood operation, or from pulpwood
specifically cut for this purpose.
Chipboard A paperboard used for many purposes that may or may not
have specifications for strength, color, or other characteristics. It is
normally made from paper stock with a relatively low density.
Chip-n-Saw A registered trade name for a machine that makes small
logs into cants, converting part of the outside of the log directly into
chips without producing any sawdust. Cants are then sawn into lumber as
part of the same operation.
Chipped Grain A machining defect in which small chips are torn from
the surface below the intended plane of cut, usually as the result of
cutting against the grain.
Chisel A metal tool with a sharp beveled edge, used to cut and shape metal, stone, or wood.
Chord The bottom or top member of a truss to which the web members are attached.
Chop Saw (Miter Saw) A hollow-ground saw in diameters from 6 to 16
inches, used for cutting off and mitering on light stock such as
moldings and cabinet work.
Chuck An attachment to hold work or a tool in a machine; lathe chucks and drill chucks are examples.
CIF Cost, Insurance, and Freight
CIFE Cost, Insurance, Freight, and Exchange
Circular Saw A power saw that has a steel disk with cutting teeth on the periphery; rotates on a spindle.
Cladding The application of one material (metal, wood, vinyl) over another to provide a protective layer against rain, and other weather elements. Cladding is designed to prevent water from infiltrating the structure and is not “waterproof.” It is also chosen for architectual design.
Clamp A fastening device to hold or secure objects tightly together
to prevent movement or separation through the application of inward
Clear (CLR) A board which is free from defects. A term including the higher grades of lumber sound, relatively free of blemishes.
Clear-Cut Cutting all trees in an area to a minimum diameter, such as 4 inches.
Cleavage In an adhesively bonded joint, a separation in the joint caused by a wedge or other crack-opening type action.
Clevis “U”-shaped metal fitting, with a pin connecting the two ends,
used for connecting cables and rigging the “C” shaped hook with a pin
through it for use in attaching or towing a cable.
CLF Hundred Lineal Feet
CLG Ceiling
CLIB California Lumber Inspection Bureau
Climax Species Plant species that remains essentially unchanged
in terms of species composition for as long as the site remains
Clinometer A hand instrument used by foresters and timber cruisers to
measure vertical angles. Such angles, when correlated with specific
distances, indicate the height of standing trees.
Close Grain Wood with narrow and inconspicuous annual rings; the term
is sometimes used to designate wood having small and closely spaced
pores, but in this sense, the term “fine textured” is more often used;
wood with more than six rings per inch
Closed Coat A piece of sandpaper whose surface is completely covered
with abrasive particles. This type of paper tends to clog easily with
sawdust and is not popularly used for woodworking.
Coarse-Grained Wood with wide and conspicuous annual rings; rings in
which there is considerable difference between springwood and
summerwood; used to designate wood with large pores.
Cock Bead Any bead which stands raised from the surface as distinct
from flush or sunk; usually taken to apply to small beads or edgings to
drawer fronts and cupboard doors.
  • Very heavy, tough, strong timber
  • High mechanical strength
  • Rich red heartwood
  • Irregular grain
  • Fine uniform texture
  • Used for cutlery handles, small tool-handles, small trinkets, fancy goods, wooden jewelry, and small decorative items
Codes Regulations detailing accepted materials and methods of
building. Usually codes are adopted by city, county, or state building
departments. Most counties promulgate local building codes.
Cohesion The state in which the constituents of a mass of material are held together by chemical and physical forces.
Cold Pressing A bonding operation in which an assembly is subjected to pressure without the application of heat.
Collapse The flattening of single cells or a row of cells in hardwood
during the drying or pressure treatment of wood characterized
externally by a caved-in or corrugated appearance.
Collar Tie A timber placed horizontally and between rafters that
control sagging or spreading of the rafters; usually placed parallel to
the grits which connect rafter pairs at a given height.
Collet In a router, the sleeve that grips the shank of a bit.
Colonial Siding AKA “Bevel Siding” is exterior cladding used for weather protection and architectural design.
Column A structural member, usually subject to longitudinal compression.
Combination Square A square that measures both 45 degree and 90 degree angles.
Come Along A hand operated ratching wrench. It uses include tightening
joinery during assembly, as a safety tie and for pulling frame
components together during erection.
Commission Man A middleman who arranges sales for a commission but does not take title to the lumber.
Commons Ordinary grades of knotty lumber.
Common Grade Lumber Lumber with obvious defects.
Common Rafters Closely and regularly spaced incline timbers that support the roof covering; independent of the bent system.
Compass An instrument for drawing circles consisting of two legs joined at a pivot hinge.
Compreg Wood in which the cell walls have been impregnated with
synthetic resin and compressed to give it reduced swelling and shrinking
characteristics and increased density and strength properties.
Compression Failure Deformation of the wood fibers resulting from
excessive compression along the grain either in direct end compression
or in bending.
Compression Wood Abnormal wood that often forms on the lower side of
branches and of leaning trucks of softwood trees; compression wood is
identified by its relatively wide annual rings, usually eccentric, and
its large amounts of summerwood, usually more than 50% of the width of
the annual rings.
Composite Assembly A combination of two or more materials bonded together that perform a single unit.
Compound Curvature Wood bent to a compound curvature, no element of which is a straight line.
Compound Cut An angled cut to both the edge and face of a board.
Compound Miter An angled cut to both the edge and face of a board; most common use is with crown molding.
Composite Decking Deck boards manufactured from wood fiber and plastic. It is sold as an alternative to wood decking. There are various composite decking manufacturers with varied degrees of quality which can lead to low product quality.
Concave An inward-curving shape.
Concentration Yard Assembles and ships the output of a number of nearby sawmills.
Concrete A mixture of cement, gravel and sand.
Concrete Mixer A machine with a large revolving drum in which concrete is mixed with other materials to make concrete.
Concrete Spatula A flat piece of metal with a projecting handle used to smooth concrete footings.
Concentrated Load The application of a relatively large force on a relatively small area.
Conditioning The exposure of a material to the influence of a
prescribed atmosphere for a stipulated period of time or until a
stipulated relation is reached between material and atmosphere.
Conduit Metal pipes used to contain electrical wiring in outdoor settings.
Conifer A type of tree that’s characterized by needle-like or scale
foliage, usually evergreen; tree that is a gymnosperm, which comes with
cones and needle-like shaped or scale-like leaves, producing wood known
commercially as softwood.
Contour Cutting A flexible blade is necessary for contour cutting and
for fairly wide curves the clumsy but efficient wooden bow to turning
Conservation Improvement, protecting, and wise use of natural
resources according to principles that will assure utilization of the
resource to obtain the highest economic and/or social benefits.
Consistency The property of a liquid adhesive by virtue of which it tends to resist deformation.
Construction Lumber Lumber that is suitable for ordinary and light construction.
Contact Angle The angle between a substrate plane and the free
surface of a liquid droplet at the line of contact with the substrate.
Convex An outward-curving shape.
Cooperage Containers consisting of two round heads and a body
composed of staves held together with hoops, such as barrels and kegs.

  • Slack Cooperage: Used as containers for dry, semidry, and
    solid products. The staves are usually not closely fitted and are held
    together with headed steel, wire, or wood hoops.
  • Tight Cooperage: Used as containers for liquids,
    semisolids, or heavy solids. Staves are well fitted and held tightly
    with cooperage-grade steel hoops.
Copolymer Substance obtained when two or more types of monomers polymerize.
Cope-and-Stick Joint A method of construction raised panel doors
where the tongues of the rails (horizontal) connect to the grooves of
the stiles (vertical).
Corbel A projection from the face of a wall or column supporting a weight.
Cord A unit of measure often used for firewood stacked 4’ long x 4’ high x 8’ long.
Core Stock A solid or discontinuous center ply used in panel-type
glued structures, such as furniture panels and solid or hollow-core
Corner The line formed by the intersection of any two surfaces of a piece of lumber; not to be confused with ‘edge’.
Cost and Freight (CF) Waterborne shipments to indicate that all
loading charges and freight to final destinations are paid by the
Cost, Insurance and Freight In addition to paying all the loading
charges and freight to final destination, the seller pay insurance
Countersink A tool that allows you to drill a hole so that the head of a screw will sit flush with the face of a board.
Coupling Agent A molecule with different or like functional groups
that is capable of reacting with surface molecules of two different
substances, thereby chemically bridging the substances.
Covalent Bond A chemical bond that results when electrons are shared by two atomic nuclei.
Crack A large radial check resulting from greater tangential than radial shrinkage.
Creep A time-dependent deformation of a wood member or adhesive joint due to sustained stress.
Crook A lumber defect where an edgewise warp effects the straightness of the board.
Crossbands In plywood with more than three piles, the veneers
immediately beneath the faces, having grain direction perpendicular to
that of the faces.
Cross Arms Designed to serve as the horizontal cross member of
utility poles, generally rough sawn full, sizes range from 3”x4” to
4”x6” by 8’ long.
Cross Breaks Transverse planes of failure in tension parallel to the
grain, caused by localized abnormal longitudinal shrinkage restrained by
adjacent normal wood.
Cross Cut (crosscutting) A cut made perpendicular to the grain of a board.
Cross Grain The deviation of grain direction from the longitudinal
axis of a piece of wood or from the stem axis in a tree. Pronounced
deviation from the surface, especially in veneer, is termed short grain.
Crotch In lumber, this refers to a piece of wood taken from the fork of a tree. Crotch veneer is highly valued for its figuring.
Crotch Grain A figure produced by cutting centrally through a tree crotch in the common plane of both branches.
Crow Bar A straight bar of iron or steel, with the working end shaped
like a chisel and often slightly bent and forked; used as a lever.
Crown Upper part of a tree, including branches and foliage.
Crown Class All trees in a stand whose tops and crowns occupy a
similar position in the canopy or crown cover. The class into which the
trees forming the crop or stand may be divided is on the basis of both
their crown development and crown position relative to the crowns of
adjacent trees and the general canopy.
Crown Cover Ground area covered by a crown; as delimited by the vertical projection of its outermost perimeter.
Crown Density Thickness, both spatially (depth) and in closeness of
growth (compactness) of an individual crown as measured by its shade
density. Collectively, crown density should properly be termed canopy
density, as distinct from canopy cover.
Crown Height Vertical distance of a standing tree from ground level
to the base of the crown, measured to the lowest live branch whorl or to
the lowest live branch (excluding epicormics), or to a point halfway
between the two.
Crown Length Vertical distance of a standing tree from the top of the
leader to the base of the crown, measured to the lowest live branch
whorl or to the lowest live branch (excluding epicormics), or to a point
of halfway between the two.
Crown Length Ratio Of a standing tree, the ratio of a crown length to a tree height.
Crown Thinning Removing superfluous live growth in a tree crown to admit light, lessen wind resistance, and reduce weight.
CS Caulking Seam
CSG Casing
Cubic Scale Estimate of the cubic-foot volume of wood fiber in a log, tree, or other wood products.
  • Color varies from golden tan to a reddish brown
  • Difficult to saw
  • High density
  • Very durable
  • Used for outdoor decking, flooring, heavy construction, railroad crossties, tool handles, and turnery
Cup A defect in the lumber where the face of the board warps up like the letter “U”.
Cup Shake A split caused by lack of cohesion between the annual rings.
Cure The change in properties of an adhesive by chemical reaction
and thereby develop maximum strength. This is generally accomplished by
the action of hear or a catalyst, with or without pressure.
Curing The setting of an adhesive by chemical reaction. Also, the drying of wood, though this is not the preferred usage.
Curl A term to describe what happens to wood as it grows. Curly wood
looks like sand on the beach or river bottom with repeated ripples in
the grain. The grain goes up and down causing the unusual look in the
wood. This is also called “Fiddleback” or “tiger” grain.
Curly Cherry
Curly Cherry
  • Heartwood varies from rich red to reddish-brown
  • Fine, straight grain
  • Smooth texture
  • Medium strength
  • Good bending characteristics
  • Low stiffness
  • Medium shock resistance
  • Works easily with hand and power tools
  • Used for furniture, flooring, high-class joinery, boat interiors, tobacco pipes, paneling, and veneers
Curly Hard Maple
Curly Hard Maple
  • Creamy-white with red tinge
  • Usually straight grain
  • High bending and crushing strength
  • Medium stiffness
  • Used for furniture, heavy-duty, flooring, piano actions, and paneling
Curly Soft Maple
Curly Soft Maple
  • Creamy-white color
  • Wavy or “curly” grain
  • Medium bending and crushing strength
  • Low stiffness and resistance to shock loads
  • Used for furniture, joinery, domestic flooring, sporting goods and paneling
Curtain Coating Applying liquid adhesive to an adherent by passing the
adherent under a thing curtain of liquid falling by gravity or pressure
Custom Drying Drying other people’s lumber
Custom Milling Surfacing or remanufacturing other peoples lumber on order.
Customer Sawing Sawing of lumber under contract, usually to given specifications.
Cut Stock Clear pieces that have been ripped and cross cut from ship
type lumber, such as stiles, rails, muntins, window sash, intended for
further manufacture.
Cut-Full Lumber Lumber intentionally manufactured in larger than
normal thickness and width, usually to allow for shrinkage; a term
sometimes confused with “full cut” lumber.
Cuttings When using hardwoods, portions of a board or plank having
the quality required by a specific grade or for a particular use.
CWT Hundred Weights
Lumber Glossary Term Definition

Dressed and Matched

D/S (DS)

Drop Siding


Lumber that has been dressed on two sides.


A rectangular channel cut partway into a board.

Dark Grain

Grain which is darker than the rest and should not be confused with pitch streaks.


Diameter at Breast Height

Dead Blow Hammer

A specialized mallet helpful in minimizing damage to the struck surface and in controlling striking force with minimal rebound from the striking surface.

Dead Load

The weight of the structure itself; which includes built-in benches, the plank system, support structure and any railings, and other permanent features.

Death Watch Beetle

A beetle that is about ¼ inch long and very destructive to structural beams.


The decomposition of wood by fungi

  • Advanced Decay – The older stage of decay in which the destruction is readily recognized because the wood has become punky, soft and spongy, stringy, pitted, and crumbly.
  • Brown Rot – In wood, any decay in which the attack concentrates on the cellulose and associated carbohydrates rather than on the lignin, producing a light to dark brown residue.
  • Dry Rot – A term loosely applied to any dry, crumbly rot but especially to that which, when in an advanced stage, permits the wood to be crushed easily to a dry powder.
  • Incipient Decay – The early stage of decay that has not proceeded far enough to soften or otherwise perceptibly impair the hardness of the wood.
  • Heart Rot – Any rot characteristically confined to the heartwood. It generally originates in the living tree.
  • Pocket Rot – Advanced decay that appears in the form of a hole or pocket, usually surrounded by apparently sound wood.
  • Soft Rot – A special type of decay developing under very wet conditions in the outer wood layers, caused by cellulose-destroying micro-fungi that attack the secondary cell walls and not the intercellular layer.
  • White Rot – Any decay or rot attacking both the cellulose and the lignin, producing a generally whitish reside that may be spongy or stringy rot, or occur as pocket rot.
Decaying Knot

A knot is disintegration of wood due to the action of wood-destroying fungi.


Trees that have broad leaves that are shed in the fall. It is usually it is a hardwood.

Decking (DKG)

Boards used for the surface of a deck; lumber expressed in nominal terms as being 2” to 4” thick and 4” and wider. Decking is usually surfaced to single tongue and groove in 2” nominal thickness. In 3” and 4” nominal thickness it may be double tongue and groove and worked with rounded or V edges, striated, or grooved. Decking is widely used for roofing and flooring.

Deck Tile

Deck Tiles are also known as elevated decking, this is a modular square wood tile system that can be used as roof decking, pool decking, exteriior decking, elevated decks, as well as interior flooring. Combinining the outdoors with the indoors has never been easier. Modular deck tiles are easy to install and are a versatile decking solution a easy remodel solution and are built with the DIY home owner in mind with ease of installation.


An irregularity found in a board that lowers its strength and value. Common defects are checks, knots, staining, etc. Conk, crook, decay, split, sweep, or other injury in the wood that decreases the amount of useable wood that can be obtained from a log.


The amount of sag in a counter, floor, joist, or shelf caused by the weight its supporting. Vertical distance between the chord and the skyline measured at midspan; frequently expressed as a percentage of the horizontal span length.


Insects that destroy foliage.


Any defect that lowers the grade or quality of a log.


Developed to reduce humidity in store rooms and basement conditions.


The separation of layers in laminated wood or plywood caused by failure of the adhesive itself or of the interface between adhesive and adhered.


Removal of part or all of the lignin from wood by chemical treatment.

Delimbing Gate

Metal grid used with a skidder for removing limbs.


Study of the identification of trees.


The weight of a body or substance per unit volume.

Density Rules

A procedure for segregating wood according to density, based on percentage of latewood and number of growth rings per inch of radius.

Depletion Allowance

Deduction from taxable income derived from wasting assets. The Internal Revenue Code of the United States permits the calculation of depletion allowances either on the basis of a percentage of the gross income from the property in question or on a per-unit-of-product basis. Depletion differs from depreciation in that the asset subject to depletion cannot be replaced; a mine or an oil field cannot be replaced in the same manner that a factory or machine can be replaced.

Design Value

A measurement of strength in lumber, involving basic properties of wood. They are: compression perpendicular to grain (Fcl), fiber stress in bending (Fb), horizontal sheer (Fv), modulus of elasticity (E), and tensions parallel to grain (Ft).


Double End Trimmed


The temperature at which atmospheric water vapor condenses out as a liquid.


Douglas Fir


Douglas Fir-Larch

Dial Gauge

A measuring instrument with a circular graduated face and a pin which activates a rotating pointer to measure variation in movement in thousandths of an inch.

Diagonal Grain

Cross grain exhibiting deviation of the growth-ring plane from the longitudinal axis, commonly the result of sawing boards other then parallel to the bark of the log.

Diameter Classes

Classification of trees based on the diameter of outside bark measured at D.B.H. In forest surveys, each diameter class encompasses approximately 2 inches: the 6-inch class would include trees 5.0 through 6.9 inches in D.B.H.

Diameter inside Bark (D.i.B.)

Diameter measurement of a standing tree or log in which the estimated or actual thickness of the bark is discounted.

Diameter Limit

Maximum diameter of trees to be cut, as in a timber sales contract.

Diameter outside Bark (D.o.B.)

Measurement of trees diameter in which the bark is included.

Diameter Tape

Tape measurer specially graduated so that diameter may be read directly when the tape is placed around a log or tree stem.


Spade-like tool used to prepare planting holes for seedlings. Dibbles are most commonly used in the South but are used in other areas for planting contained seedlings.

Diffuse-Porous Wood

Certain hardwoods in which the pores tend to be uniform in size and distribution throughout each annual ring or to decrease in size slightly and gradually toward the outer border of the ring.




Framing lumber; generally applied to lumber when the nominal size is 2 inches thick and 2 or more inches wide. The National Grading Rule for Softwood Dimension Lumber defines “dimension” as lumber from 2 through 4 inches thick and 2 inches and wider.

Dimension Lumber

Lumber that is from two inches thick up to, but not including, five inches thick, and that is also two or more inches in width. Dimensions can also be classified as framing, joists, planks, rafters, etc.

Direct Cost

Cost that varies in direct proportion to production and is attributable to a specific factor of production.

Directional Felling

Predetermining the way a tree will land when it hits the ground. When shears are used, the wedge-shaped blade provides a lever that directs the tree into its lay.

Direct Seeding

Spreading seeds over the forest seedbed by hand or machine. This practice is used to assist or supplement natural seed fall and to achieve regeneration.


Changes in the color of wood which affect only its appearance.



Dolly Varden Siding

A pattern with a thick and a thing edge and lap joint.

Dominant Trees

The most numerous and vigorous species in a mixed forest. Larger-than-average trees with well-developed crowns extending above the general canopy level and receiving full light from above and partial light from the side.


Synonymous with ‘decay’ and are any form of decay which may be evident as either a discoloration or a softening of the wood.

Double-Action Shear

Mechanized cutting tool for felling trees; works like a pair of scissors. One blade is slightly offset, but both work against the other. Some work edge to edge.

Double-Drum Winch

A winch consisting of two drums controlled separately, one for the dragline and the other from the haul-back line. Sometimes mounted on and powered by a tractor.

Double End Trimmed (DET)

Both ends cut reasonably square by a saw.

Dovetail Joint

A method of joining wood at the corners by the use of interlocking pins and tails; a tenon that is shaped like a dove’s spread tail to fit into a corresponding mortise.


A wood pin used to align and hold two adjoining pieces.

Dowel Center

A circular metal pin with a raised point that is inserted into a dowel hole and used to locate the exact center on a mating piece of wood.

Dowel Woodworking Tip

A cylindrical wooden pin that is used to reinforce a wood joint.


A type of Japanese woodworking saw that is used for fine joinery work such as dovetails. Its western equivalent is a back saw.

Draw Knife

A tool having a blade with a handle at each end; by drawing it towards you, you can shave surfaces.

Drawer Slide

A mechanism used to make drawers slide in and out.

Drawer Stop

A device installed in a cabinet to limit the drawers’ movement.

Dressed and Matched (D&M)

Lumber that has been worked with a tongue off center on one edge of each piece and a groove on the opposite edge to provide a close joint by fitting two pieces together.


Shaping the cutting edge of a chisel to correct the bevel.


An implement with cutting edges or a pointed end for boring holes in hard materials, usually by a rotating abrasion or repeated blows; a bit.

Drive Wheel

The portion of a band saw’s pulley-like drive system that propels the blade forward.

Rop Siding (D/S; DS)

A lumber pattern with lap or tongue and groove joints.


Seasoned, usually to a moisture content of less than 19%.

Dry Kiln

An enclosed chamber in which temperate and humidity conditions are subject to control for the purpose of drying lumber.

Dry Rot

A term loosely applied to many types of decay but especially to that which, when in an advanced stage, permits the wood to be easily crushed to a dry powder; the term is actually a misnomer for any decay, since all fungi require considerable moisture for growth.

Dry Strength

The strength of an adhesive joint determined immediately after drying under specified conditions or after a period of conditioning in a standard laboratory atmosphere.


A paneling product used as an interior wall and ceiling covering made of gypsum plaster with paper facings. The gypsum plaster may be reinforced with recycled fiber.


Generally lumber of a low grade used to separate and bind ship cargo; stakes, stripes and other pieces that are needed in holding and protecting merchandise on railroad cars and truck shipments.


A general term for permanence or lastingness; frequently used to refer to the degree of resistance of a species or of an individual piece of wood to attack by wood-destroying fungi under conditions that favor such attack.

Lumber Glossary Term Definition



Edge & Center Bead Two Sides


Edge & Center V One Side


Edge & Center V Two Sides

Earned Harvest

A timber management concept used by the USDA Forest Service. This allows the timber manager an immediate increase in the allowable cut when the manager applies intensive management techniques that will accelerate future timber growth.

Early Wood (Springwood)

The first part of the trees’ rings to form after winter hibernation. Earlywood is often characterized by larger cells and a lower density.

Eased Edges (EE)

Slightly rounded surfacing on pieces of lumber to remove sharp corners. Lumber 4 inches or less in thickness is frequently shipped with eased edges unless otherwise specified.


A legal right for restricted use of property by the easement holder. Easements are granted to utility companies so they may service the utility lines running through a property. Decks should not be built on the area described by an easement because access granted by the easement may require the deck to be torn down or removed.


Edge bead one side.


Edge bead two sides.


The study of animals and plants in relation to their biological and physical surroundings.


Complex ecological community and environment forming a functional whole in nature.


The narrow face of a rectangular-shaped piece of lumber.

Edge Banding

Veneer that usually has an adhesive to stick to plywood edging.

Edge Grain

Lumber sawed parallel with the pith of the log and approximately at right angles to the growth rings; that is, the rings form an angle of 45 degrees or more with the wide face if the piece.

Edge Guide

A straightedge that is used to guide tools, such as a circular saw or router, along a work-piece.

Edge Joining

Smoothing and squaring the edge of a board so that it can be glued up evenly to another piece.

Edge Trimmer

Tool used to trim edge banding.


Eased Edges


Edge (vertical) Grain


A property of a material that causes it to return to its original dimensions after being deformed by loading.


A macromolecular material that, at room temperature, is deformed by application of a relatively low force and is capable of recovering substantially in size and shape after removal of the force.


In a dust collection system, a fitting used to torn corners.

Electron Beam Welding

A metal joining process that uses a narrow stream of electrons to produce a highly concentrated heat source.

Elevated Deck

A deck requiring a structure of beams, footings, and posts to raise it to the desired level. Often used so that the height of the deck is the same as interior floors, making access to the deck from the house easier.


End Matched

Embedded Grit

Grit that is embedded in wood chips in the process of whole-tree chipping. This grit may be extremely difficult to remove when using chips in paper and pulp manufacture.


A loss in strength or energy absorption without a corresponding loss in stiffness. Clear, straight grained wood is generally considered a ductile material; chemical treatments and elevated temperatures can alter the original chemical composition of wood, thereby embrittling the wood.

Empty-cell Process

Any process for impregnating wood with preservatives or chemicals in which air is imprisoned in the wood under the pressure of the entering preservative and then expands, when the pressure is released, to drive out part of the injected preservative.

Encased Knot

The dead portion of a branch embedded in the stem by subsequent growth of a tree.

End Checks

A drying defect caused by the ends of the boards drying faster than the rest of the wood. This can usually be prevented by sealing the end grain. Using an end grain sealant protects against end checks in decking.

End Coating

The process of sealing the ends of the boards to prevent checking caused by unrestrained evaporation of moisture. Also known as “end grain sealing.”

End Grain Lumber grain as seen from one end of the board where elongated pores are exposed. End grain can absorb and release liquid and liquid vapors.
End Joists

The joists at the end of a series of parallel joists.

End-Match (EM)

To tongue and groove the ends of matched lumber.


A lengthwise separation of the wood fibers at the end of a piece of lumber.

Energy Wood

Wood that has been delivered to paper and pulp mills, specifically for burning in boilers; wood to be utilized for heat or other energy products. This includes forest, industrial, urban, and other wood waste, as well as whole-tree chips.


The outermost layer of cells on the primary plant body; often with strongly thickened and cuticularized outer walls; sometimes consisting of more than one layer of cells.

Epoxy Glue

A two part glue that practically glues anything to anything, including metal to metal.


Englemann Spruce

Equilibrium Moisture Content (EMC)

When the level of moisture in a board is equal to the moisture in the surrounding air.

European Hinge

A hidden style hinge fastened to the door with a cup hole.


Edge V one side


Edge V two sides


A stand of trees in which there are only small differences in age among the individual trees.

Even-Aged Management

A silvicultural system in which the individual trees originate at about the same time and are removed in one or more harvest cuts, after which a new stand is established.

Expansion and Contraction

Boards expand when they heat up and contract when they cool down. This must be accounted for when spacing deck boards.

Export Sale

Sale of lumber to be shipped to a foreign country.


Wholesaler or broker selling to a foreign market.


A substance, generally having some adhesive action, added to an adhesive to reduce the amount of the primary binder required per unit area.

Extension Cord

A flexible, insulated, electric wire fitted with a plug at one end and one or more outlets on the other, allowing one to plug in.


Substances in wood, not an integral part of the cellular structure, that can be dissolved out with hot or cold water, ether, benzene, or other relatively inert solvents.

Extreme Fiber Stress in Bending (Fb)

The allowable unit stress used in the design of bending members such as beams, trusschords, joists, and rafters.

Extrusion Spreading

A method of adhesive application in which adhesive is forced through small openings in the spreader head.

Lumber Glossary Term Definition

When a board has one side that is wider than the other, the wider side is referred to as the face (as opposed to the edge). This may also refer to the side that is to visible in the finished item.

Face Flaps

Used for writing bureaus and cabinets where it is essential to preserve an uninterrupted flush writing surface are hinged with back flap hinges, and can be rebated/rabbeted over the carcass sides.

Face Frame

In cabinetmaking, a face frame is a flat frame attached to the front of a carcase. The face frame is used to conceal the exposed edges of plywood panels used to build the carcase.

Face Side

The wide surface of a piece of lumber; the wide surface showing the better quality or appearance from which a piece is graded.

Face Width

The width of the face of any piece of lumber; in tongued or lapped (rabbeted) lumber, it does not include width of tongue or lap.

Face Veneer

High quality veneer that is used for exposed surfaces on plywood.

Factory Lumber

Lumber intended to be cut up for use in further manufacture’ it is graded on the basis of the percentage of the area which will produce a limited number of cuttings of a specified, or a given minimum, size and quality.


Lumber not up to a particular grade.

FAS (First and Second)

Mixed domestic hardwood lumber grade is the highest grade of hardwood lumber. In most species, a board must be 6” or wider, 8’ or longer. Walnut and butternut are the exceptions.

Fascia (facia)

A broad, flat, horizontal surface, sometimes used to cover a joint, or as the other edge of a cornice.


Generic term for bolts, nails, bolts, and other connecting devices.


Extreme fiber stress in bending


Feet board measure


Flat car paper wrapped


A piece of wood with thin “fingers” that hold a board against a fence or down against the table of a power tool; usually a table saw or router.

Feed Rate

The distance that the stock being processed moves during a given interval of time or operation cycle.

Feet Board Measure (FBM, FT, BM)

A term used to indicate a specific unit of measure.

Feet Surface Measure (FTSM)

A term used to indicate a specific unit of measure


A straight guide to keep a board a set distance from a blade or other cutters.


Flat of slash grain.

Fiber Saturation Point

The stage in the drying or wetting of wood at which the cell walls are saturated and the cell cavities free from water. It applies to an individual cell or group of cells, not to whole boards.


A threadlike component of cell walls, invisible under a light microscope.


A type of washboard-like figure that occurs in some species of wood with wavy grain; a decorative wood figure caused by wavy grain. Fiddleback veneer is prized for its character and widely used for musical instruments.


Any distinctive appearance on a longitudinal wood surface resulting from anatomical structure, irregular coloration or defects.

Figured Bubinga


  • Medium red-brown with purple veining
  • Straight to interlocked grain
  • Moderately coarse but even texture
  • Low bending characteristics
  • Works easily with hand and power tools
  • Pre-drilling is required for nailing
  • Used primarily as a veneer for cabinetwork. Also used for knife handles, and fancy goods.

A substance that is used to fill pores and irregularities on the surface of material to decrease the porosity before applying a finishing coat.

Filtch Matched

See ‘bookmatched’.

Finger Joint

A method of joining two pieces of lumber end-to-end by sawing a set of projecting “fingers” that interlock into the end of each piece. This makes for a strong glue joint when the pieces are pushed together.


A term indicating the higher grades of lumber, sound, relatively free of blemishes.

Finished Size

The net dimensions after surfacing.


Any evergreen coniferous tree, especially of the genus Abies, with needles borne singly on the stems.

Fire Endurance

A measure of the time during which a material or assembly continues to exhibit fire resistance under specified conditions of test and performance.

Fire-Retardant A chemical applied to lumber or other wood products to slow combustion and flame spread.
Fire Retardant Treated Wood

As specified in building codes, a wood product that has been treated with chemicals by a pressure process of treated during the manufacturing process for the purpose of reducing its flame spread performance in an ASTM E 84 test conducted for 30 minutes to performance levels specified in the codes.

Firm Heart Stain

A brownish or reddish discoloration, and in the grades where specified, does not affect the use of the piece to any greater extent than the other characteristics of the grade.


For dust collection, accessories that are used to connect hoses, pipes, and tools within a dust collection system.


A small flat wood particle of predetermined dimensions, uniform thickness, with fiber direction essentially in the plane of the flake; in overall character resembling a small piece of veneer.

Flame Spread

The propagation of a flame away from the source of ignition across the surface of a liquid of a solid, or through the volume of a gaseous mixture.

Flat Car Paper Wrapped (FCPW)

Lumber loaded on an open rail car after being strapped into units and wrapped in weather resistant material. Plastic or papers are commonly used.

Flat Grain (F.G.)

Lumber sawn approximately parallel to the annual growth rings so that all or some form an angle of less then 45 degrees with the surface of the piece.




A thick piece of lumber with or without wane (bark) on one or more edges suitable for remanufacturing.


A lumber pattern with smooth face and tongue and groove edges.


When two adjoining surfaces are perfectly even with one another.


Free on board


Free of heart center

Foot (FT)

A unit of lineal measurement usually used to indicate the length of lumber.


The below-ground support of a deck’s post; usually made from concrete.


Area managed for the production of timber and other forest productions or maintained as wood vegetation for such indirect benefits as protection of catchment areas or recreation.


Establishment of a forest, artificially or naturally, or an area, whether previously forested or not.

Forest Economics

The branch of forestry concerned with the forest as a productive asset subject, in relation to economic principles.

Forest Floor

A general term for the surface layer of soil supporting forest vegetation; includes all dead vegetation on the mineral soil surface in the forest as well as litter and unincorporated humus.

Forest Management

The practical application of scientific economic, and social principles to the administration and workings of a specific forest area for specified objectives.

Forest Practice

Any activity that enhances and/or recovers forest growth or harvest yield, such as fertilization, harvesting, planting, site preparation, and thinning. Road construction or reconstruction within forest lands for the purpose of facilitating harvest or forest management. Any management of slash, resulting from the harvest or improvement of tree species.

Forest Residuals

Sum of unused and wasted wood in the forest, including logging residues, annual mortality, and dead, rough, and rotten trees. Unmerchantable material normally left following conventional logging operations other than whole-tree harvesting.


A profession embracing the art of creating, business, and science, conserving, and managing forests, and forest lands for the continuing use of their materials, resources, and other forest products.

Forest Type

Classification of forest land in terms of potential cubic-foot volume growth per acre at the culmination of mean annual increment (C.M.A.I.), in fully stocked natural stands. Classification of forest land is based on the species forming a plurality of live-tree stocking. Type is determined on the basis of species plurality of all live trees that contribute to stocking.

Forest Stewardship Council

An independent, non-governmental organization established to promote responsible management of the worlds forests and is probably the most well-known forest certification program worldwide. FCS standards of responsible forestry are applied to management of the forest land. A chain-of-command (COC) certification ensures that forest products that carry the FSC label can be tracked back to the certified forest from which they came.


Composed of layers of Kraft paper impregnated with phenolic resins.

Forster Bit

These have a center spur and circular timbers with cutting teeth that cut clean flat bottomed holes.

Found Curve

Naturally occurring crooked timbers usually with two sides sawn and two sides with the bark removed; used as beams, knee braces, and posts.


Lumber used for structural members in a house or other building. This is the skeleton to which floors, roofs, and sides are attached.

Framing Chisel

A large chisel with long, heavy blades, strong enough to be hit with a heavy mallet.

Framing Lumber

A term generally applied to lumber when the nominal size is 2 through 4 inches thick and 2 inches and wider; lumber used to construct a building or structure.

Framing Square

A flat piece of metal shaped like an “L”, with measurements along both legs of the “L”; commonly used when building decks for marking lines perpendicular to the length of lumber.

Free Along Side

Seller delivers the shipment within reach of ship’s loading tackle. All dock charges and freight from point of origin to the dock have been paid by the seller. Freight charges to the final destination are billed to the buyer.

Free of Heart Center (FOHC)

Lumber sawn to exclude the heart center or pith of the log.

Free on Board (FOB)

Refers to a named point to which the seller will deliver and load lumber on board transportation equipment at no additional charge to the buyer. Freight or other charges to final destination are for the buyers account.

Freestanding Platform Deck

A deck supported entirely by its own structure, typically used for remote decks.

Freight Measure

“Board Measure” contents of lumber-when calculated from measurements of over-all dimensions; it is used only for displacement measurements for freight purposes.

Fret Saw

A saw with a very fine toothed blade used for delicate cuts in thin material.


A saw blade made with one piece of carbon steel used at high speeds to soften metal for removal.

Friction Sawing

Usually a type of band sawing that uses high speed to generate heat to soften the metal in front of the blade.






Feet surface measure

Full Length

Cut so the ends can be squared to exact length tallied.

Full Sawn Lumber

Green Lumber, cut full to a specified size without variation undersize at time or original inspection.

Full-Cell Process

Any process for impregnating wood with preservatives or chemicals, in which a vacuum is drawn to remove air from the wood before admitting the preservative.

Full-Cut Lumber

Lumber that in thickness and width measures fully up to specified sizes; a term sometimes confused with ‘cut-full’ lumber, the latter admitting lumber intentionally manufactured in larger than nominal thickness and width.


A chemical that kills fungi; used to control fungal diseases in greenhouses and nurseries.

Fungus Stain

Lumber stain caused by fungus growth in wood; fungi can be either of the sapwood-staining or decay-producing types.


Wood material that has been reduced for incorporation into conventional wood-based composites; including flakes, particles, and fiber.

Free Water

Moisture found in the cell cavities of wood.

Lumber Glossary Term Definition



The side-to-side thickness of a band saw blade.


Coating a piece of metal with zinc, a metal that resists corrosion. Look for hot-dipped galvanized pieces when selecting metal parts for a deck. The hot-dipped method of galvanized metal provides more protection than coated galvanizing.


A tool used to determine depth, width, and/or height of an object.

Gelatinous Fibers

Modified fibers that are associated with tension wood in hardwoods.


A machine that converts one form of energy into another; especially mechanical energy into electrical energy, as a dynamo, or electrical energy into sound, as an acoustic generator.


A large or principal beam used to support concentrated loads at isolated points along its length.


Major horizontal timber that connects posts.


The distance around a tree; circumference.


Originally, a hard gelatin obtained from hides, tendons, cartilage, bones, etc., of animals; also, an adhesive prepared from this substance by heating with water. Through general use, the term is now referred to as ‘adhesive’.

Glue Joint

A special interlocking groove pattern that is used to join two pieces, edge to edge, securely.

Glue Laminating

Production of structural or nonstructural wood members by bonding two or more layers of wood together with adhesive.


A shorthand version of glue laminate. Glue lamination is a process in which individual pieces of lumber or veneer are bonded together with an adhesive to make a single piece, with the grain of each piece parallel to the grain of each of the other pieces.

Good One Side

Plywood with one side patched solid and sanded, the other side will be rough and have open knot holes.

Goncalo Alves (Tigerwood)
  • Reddish-brown heartwood
  • Irregular and interlocked grain
  • Medium texture
  • Hard, heavy, and dense
  • Used for high class furniture and cabinet making, fancy goods, decking, and architectural paneling

A chisel like tool with a curved cutting edge.


A designation of the quality of a log or wood product such as lumber, plywood, or veneer.

Grade-Level Deck

A deck flush with, or slightly above, ground level. Grade-level deck joists usually rest directly on the footings or piers below.

Grade Mark

A stamp or symbol indicating the grade, quality, and/or intended use of a piece of lumber, plywood, or other wood products. To be recognized as “grade marked”, the product must bear an official stamp issued by a grading agency and must be applied by a qualified grader; or it must be accompanied by a certificate attesting to the grade.

Grade Stamped

Grade indicated with official stamp impression.


Amount by which the grade decreases or increases in a unit of horizontal distance.

Grading Rules

A set of criteria by which to judge various pieces of lumber of panels in terms of appearance, strength, and suitability for various uses. Regional grading agencies draw up rules for grading based on the voluntary product standards issued by the US Bureau of Standards.


A general term referring to the alignment, appearance, arrangement, color, direction, and size of wood fibers in a piece of lumber. Among the many types of grain are coarse, curly, fine, flat, open, spiral, straight, and vertical.

  • Close-Grained – Wood with narrow, inconspicuous annual rings. The term is sometimes used to designate wood having small and closely spaced pores.
  • Coarse-Grained – Wood with wide conspicuous annual rings in which there is considerable difference between earlywood and latewood. The term is sometimes used to designate wood with large pores, such as oak and walnut.
  • Cross-Grained – Wood in which the fibers deviate from a line parallel to the sides of the piece. Cross grain may be either diagonal or spiral grain or a combination of the two.
  • Curly-Grained – Wood in which the fibers are distorted so that they have a curled appearance, as in ‘Birdseye’ figure.
  • Diagonal-Grained – Wood in which the annual rings are at an angle with the axis of a piece as a result of sawing at angle with the bark of the tree or log.
  • Edge-Grained – Lumber that has been sawed so that the wide surfaces extent approximately at right angles to the annual growth rings.
  • Fiddleback-Grained – Figure produced by a type of fine wavy grain found in species of maple, for example, that is traditionally being used for the backs of violins.
  • Flat-Grained – Lumber that has been sawn parallel to the pith and approximately tangent to the growth rings.
  • Interlocked-Grained – Grain in which the fibers put on for several years may slope in a right-handed direction, and then for a number of years the slope reverses to a left-handed direction, and later changed back to a right-handed pitch.
  • Open-Grained – Common classification for woods with large pores such as oak, and walnut.
  • Plain-Sawn – Also referred to as Flat-Grained Lumber.
  • Quarter-Sawn – Also referred to as Edge-Grained Lumber.
  • Side-Grained – Also referred to as Flat-Grained Lumber.
  • Spiral-Grained – Wood in which the fibers take a spiral course about the trunk of a tree instead of the normal vertical course. The spiral may extend in a right-handed or left-handed direction around the tree trunk.
  • Straight-Grained – Wood in which the fibers run parallel to the axis of a piece.
  • Vertical-Grained – Also referred to as Edge-Grained Lumber.
  • Wavy-Grained – Wood in which the fibers collectively take the form of waves or undulations.
Grain Pattern

Three distinct grain patterns:

  • Plain Sawn
  • Vertical
  • Curly

Plain Sawn has an arching grain. Vertical has pinstripes with no growth rings over 45 degrees perpendicular to the face and Curly is the rarest.

Green Lumber (Live)

Freshly cut, unseasoned, not dry. Lumber with a moisture content of 30% or more.


A measure of the size of abrasive particles used in the manufacturing of sandpaper. Grit can also be measured as the number of particles in a square inch of sandpaper surface.

Gross Measure

‘Board Measure’ contents of lumber when calculated from measurements of named sizes; same as nominal measure.

Ground Clearance

General term for removing unwanted roots, slash stumps, stones, and vegetation from a site before Afforestation or reforestation. Generally, the distance by which a vehicle’s lowest point, exclusive of the wheel assembly, clears the ground; measured perpendicularly from that point to a plane surface on which the vehicle rests.

Ground-Fault Circuit Interrupter (GFCI)

An electrical safety device that instantly shuts down a circuit if leakage occurs; greatly reduces the risk of electrical shock. These devices are built into outlets and are required by code for outdoor receptacles.

Ground Length

Extent to which the ground around a tree is broken by gullies, or swells ridges, rock outcrops, and sharp slope changes.

Growth Ring

The layer of wood growth put on a tree during a single growing season.

Guillotine Shear Type of carrier-mounted, single-action anvil shear used in mechanized cutting where the blade is pushed through the stem and away from the carrier, instead of being pulled as in the draw shear.

The curved area between two band saw teeth into which the chip curls.

Gullet Depth

The distance from the tooth tip to the bottom of the gullet.

Gum Canal

An intercellular cavity, found in woods that may contain gum, latex, and resins.

Gum Pocket

An excessive local accumulation of gum or resin in the wood.

Gunstock Post

A post having an increased size at its top, providing extra strength for intersecting joinery.

Lumber Glossary Term Definition
H or M

Hit or Miss


Hit and Miss


The use of a long blade mounted in a bow-shaped frame. Cutting takes place using a reciprocating, or back-and-forth, motion.

Half-Blind Dovetail

A dovetail joint where the cut does not go all the way through the board. The ends of a half-blind dovetail are concealed.


A joint in which two timbers are let into each other.


A hand tool with a heavy rigid head and a handle; used to deliver an impulsive force by striking.

Hammer Beam

A horizontal timber projecting from the top of the wall or rafter that supports a wood truss. The design creates a large roof span with relatively short timbers.

Hammer Drill (Rotary Hammer)

A rotary drill with a hammering action. The hammering action provides a short, rapid hammer thrust to pulverize relatively brittle material and provide quicker drilling with less effort.


A timber squared off and shaped by hand.

Hand Plane

A tool to smooth and true wood surfaces, consisting of a blade fastened in frame at an angle with hand grips to slide it along the board. There are several different parts that make up a hand plane:

  • The Knob – A handle on the front portion of the hand plane that gives you more control when pushing the hand plane through the wood. The knob can be in the shape of a handle, or it can be more of a knob shape.
  • The Handle – The handle is the back grip of the hand place that is sued to push the plane across through the wood that you are hand planning. The handle is often curved and attached to the hand plane at a slight angle for a more comfortable grip.
  • The Frog – The frog is a metal plate that sits at an angle in the middle of the hand plane, where there is a notch to allow the plane iron (part of the planer that cuts the wood) to protrude. This is attached with screws and has an adjustment lever at the top of the frog. The adjustment level moves a set screw that will dictate the depth of the plane iron once installed.
  • Plane Iron – The plane iron is the cutting blade of the hand planer. This blade has a very sharp edge and protrudes from the middle of the bottom of the hand planer by a very small amount allowing for smoother planning. The plane iron is held in place on the frog, which allows for minor adjustments once the plane iron is mounted. The plane iron is then sandwiched between the plane iron cap and the lever cap to lock the plane iron in place and prevent the blade from shifting when the hand plane is in use.
  • Plane Iron Cap – This goes directly over the plane iron to hold it into place and keep the blade form pushing up when cutting through wood. The plane cap is held in place by the lever cap.
  • Lever Cap – A lever cap is the component that locks the plane iron, plane iron cap, and the frog together. The lever cap slips over the mounting screw, into which all of these pieces of the hand plane slide. The screw is then tightened with a screw driver to lock the plane iron in position.
Hand Tools

Are the basic tools of woodworking and the processes of sawing, chiseling, and smoothing wood.


A vehicle moved by a pair of short, endless articulated belts, called tracks, driven by tractor tires. Steering is by a pair of ordinary wheels in front. The whole vehicle is termed a half-track.


A substance or mixture of substances that is part of an adhesive and is used to promote curing by taking part of the reaction.


The property of wood that is indicated by a resistance to cutting, scratching, denting, pressure or wear.

Hard Maple
  • Creamy white with a reddish tinge
  • Usually straight grained
  • Fine texture
  • High bending and crushing strength
  • Difficult to work with
  • Used for furniture, joinery, heavy-duty flooring, piano actions, plywood, and paneling.

A type of manufactured board similar to particle board but with a much smoother surface. A common brand of hardboard is Masonite.


A general term referring to any variety of broad-leaved, deciduous trees, and the wood from those trees. The term has nothing to do with the actual hardness of the wood; some hardwoods are softer then certain softwood (evergreen) species.

Harvest Functions
  • Bunching – Gathering and arranging trees or part of these in small piles.
  • Chipping – Breaking or cutting trees into small pieces of controlled fiber length.
  • Debarking – Removing the outer protective layer (bark) from trees or parts of trees.
  • Delimbing – Removing branches from trees.
  • Felling – Cutting or uprooting standing trees, causing them to fall as a result of the cutting or uprooting.
  • Forwarding – Transporting trees or their parts by carrying them completely off the ground rather then pulling or dragging them along the ground. Also known as prehauling.
  • Loading – Picking up trees or their parts of trees, from the ground or from a vehicle, transporting them, and then piling them into another vehicle.
  • Piling – Picking up tree-length logs or bolts and depositing them in large piles so that the logs are horizontal and parallel to each other and the ends are approximately in the same vertical planes.
  • Skidding – Transporting trees or parts of trees by dragging or trailing them.
  • Slashing – Cutting felled and limbed tress into lengths. Also known as bucking.
  • Topping – Cutting off the top of a tree at a predetermined, minimum diameter.
  • Yarding – Initial hauling of a log from the stump to a collection point.

Removing merchantable trees.

Harvesting Machine Classifications

The mobile machinery used in forestry, then is classified into major types by the specific functions or combination of functions preformed. Further classification may be required to differentiate between machines with basic conceptual differences that effect recognition of performance but perform the same functions. One or more of the following sub-classifications may be used when necessary. Multifunction machines are named by a composite of the functions, listed in the order the functions are preformed.

  • Single Function Machines
    • Bucker – See Slasher
    • Chipper – Designed to chip whole trees or their parts
    • Debarker – Designed to remove the bark from trees.
    • Drum Debarker – Used to remove bark from pulpwood. Bolts tumble together forcibly and repeatedly in their passage through a large drum, rubbing off bark as they roll against each other and against the corrugated interior of the drum. The drum’s corrugated interior keeps the bolts tumbling as the drum rotates, while gravity and the force of additional incoming bolts force the wood through.
    • Ring Debarker – Used to remove bark from saw logs and veneer bolts. As the in-feed conveyor advances the log longitudinally into the feed rollers, it automatically centers the log in the rotating mechanical ring. The ring has five crescent-shaped fingers that open automatically as the feed rollers force the log against them and the log advances through the rotating mechanical ring.
    • Delimber – Self-propelled or mobile machine designed to remove all limbs from trees with flailing chains or knives.
    • Feller – Self-propelled machine designed to fell standing trees.
    • Forwarder – Self-propelled machine, usually self-loading, designed to transport trees or their parts by carrying them completely off the ground.
    • Loader – Self-propelled or mobile machine with grapple and supporting structure designed to pick up and discharge trees or their parts for the purpose of loading or piling. Operation may be swing-to-load, slide-to-load, or travel-to-load. Also known as hydraulic loader or knuckle-boom if it swings to load and has hydraulically activated boom members.
    • Mobile Yarder – Self-propelled or mobile machine designed to perform cable logging with the use of a tower that may be integral to the machine or a separate structure.
    • Skidder – Self-propelled machine designed to transport trees or pans of trees by dragging or trailing.
    • Cable Skidder – Uses a man winch cable and cable chokers to assemble or hold a load.
    • Clam-Bunk Skidder – Uses an integrally mounted loader to assemble the load and clam or top-opening jaws to hold it. A grapple skidder uses a grapple or bottom-opening jaws to assemble and hold a load.
    • Slasher – Mobile machine designed to cut felled trees to a predetermined length with a shear or saw. Also known as a bucker.
    • Swath Cutter – Self-propelled harvesting machine capable of continuous movement while simultaneously felling multiple stems across a 6 to 8 foot wide swath.
  • Multi-Function Machines
    • Delimber Bucker – See Delimber Slasher
    • Delimber Buncher – Used to delimb trees and arrange logs in piles on the ground.
    • Delimber Slasher – Used to delimb and slash trees. Also known as a Delimber bucker.
    • Delimber Slasher Bucker – Used to delimb and slash trees and arrange logs in piles on the ground.
    • Feller Buncher – Self-propelled machine designed to fell standing trees and arrange them in bunches on the ground. May travel-to-bunch or swing-to-bunch.
    • Feller Chipper – Used to chip and fell whole trees.
    • Feller Delimber – Self-propelled machine designed to fell and delimb trees.
    • Feller Delimber Buncher – Self-propelled machine designed to fell, delimb, and arrange the trees in bunches. A feller Delimber Slasher buncher is a self-propelled machine designed to fell, delimb, and slash trees and arrange the tree parts in piles on the ground.
    • Fell Delimber Slasher Forwarder – Self-propelled machine designed to fell, delimb, and slash trees and carry tree parts to a landing.
    • Feller Forwarder – Self-propelled, self-loading machine designed to fell standing trees and transport the stems by carrying them completely off the ground.
    • Feller Skidder – Self-propelled, self-loading machine designed to fell standing trees and transport them by skidding.
    • Harvester – Self-propelled multifunction machine that may be capable of operating as a swath cutter but also performs chipping and/or forwarding functions in addition to felling.
    • Limited-Area Feller Buncher – Feller-buncher with a shear mounted on a knuckle-boom, allowing the machine to reach and fell several trees while remaining stationary.
    • Processor – Multifunction machine that does not fell trees but handles two or more subsequent functions.
    • Slasher Buncher – Used to cut logs to predetermined lengths and arrange them in piles on the ground.

Hardwood or better said hardwood lumber is generally milled from the species of woods considered to be hard,l this is a direct reference to the hardness of the wood such as measured by the janka scale,the minumum hardness for a wood to be considered a hard wood is often debated. In general regardless of where it lands on the jank scale a rule of thumb would be, hardwood comes from a deciduous tree which loses its leaves yearly and softwood comes from a conifer, which remains evergreen. Hardwoods tend to be slower growing, and are therefore usually more dense.

Hardwood Wrench

A tool used to hold deck boards straight while fasteners are being installed. It locks into place and applies much more bending power then other methods of straightening deck boards.


Conveying wood from a loading point to an unloading point.

Haul-Back Block

Block used to guide the haul-back line.

Haul-Back Line

Rope used in cable logging to haul the main line and its fittings back to the point where the logs are to be attached.


The part of the whole timber beyond the shoulder which is let into another timber.

Haywire Operation

Contemptuous term for logging operation that has poor equipment.


Hollow Bark

Head Rig

Principal machine in a sawmill; used for initial breakdown of logs by sawing along the grain. Logs are first cut into cants on the head rig before being sent on to other saws for further processing. This is also known as head saw.

Head Saw

In a sawmill, the large band saw or circular saw used to size the log into lumber.

Head Tree

Spar tree at the landing of a skyline logging operation. This is also known as Head Spar.


A beam fitted between trimmers and across the ends of tailpieces in a building frame; a horizontal support at the top of an opening.

Heart Content Hardwood is formed when sapwood becomes inactive and is infused with additional resin compounds. It develops slowly in the center of the tree as the tree matures. The older the tree, the higher the heart content.
Heart Pith

The soft, spongy heart of a tree, which may appear on the surface of sawn timber.

Heart Shake

A split that starts at the heart of a log.

Heart Stain

A discoloration of the heartwood.


The dead inner core of a tree. Usually must be harder and darker than the new wood.

Heel Boom

Loading boom that uses tongs to heel or force one end of a log against the underside of the boom.

Heel Tackle

System of lines and blocks used to tighten the skyline.




Hemlock – True Firs


A cellulose-like material in wood that is easily decomposable as by dilute acid.


Chemical used to kill or retard the growth of plants; weed killer.

Herringbone Pattern

In veneering, a herringbone pattern that is formed when successive layers of veneers are glued up so they form a mirror image. Usually this pattern slants upwards and outwards, similar to a herringbone.

  • Brown to reddish-brown color
  • Typically straight grained
  • Coarse texture
  • Pre-boring for nailing is required
  • Used for hammers, axes, gold clubs, lacrosse sticks, plywood and decorative veneers.
Hide Glue

Prepared by boiling bones, hides, etc. in water, and obtaining a hard cake form which must be broken up in an old piece of sacking and soaked for 12 hours before heating.

High Grade

Good quality timber.

High-Lead Logging

Wire rope system that involves yarding in logs or trees by means of a rope passing through a block at the top of the head spar.

High-Speed Steel

A particular grade of steel that offers improved hardness and wear resistance. High-speed steel is often used to make various cutting tools.

High Rigger

Logger who tops trees and rigs them with blocks, guys, and lines.

High Stump

A stump that is higher then a specified standard.


A mechanical device that connects two solid objects, allowing rotation between them.

Hit and Miss

In surfaced lumber, hit and miss is a series of skips by planer knives with surfaced or entirely rough.

Hit or Miss

Pits or spots in wood caused by fungi. It develops in the living tree and does not develop further in wood in service.

Hollow-Core Construction

A panel construction with faces of plywood, hardboard, or similar material bonded to a framed-core assembly of wood lattice, paperboard rings, which support the facing at spaced intervals.


A drying defect that occurs when the lumber undergoes severe case hardening in the early stages of drying; appears as deep, internal checks.


Machines used to grind wood into chips for use as fuel or for other purposes. The wood used for this is usually wasted wood unfit for lumber or other uses.

Hogged Fuel

Fuel made by grinding wasted wood in a hog; a mix of wood residues such as sawdust, planer shavings, and sometimes coarsely broken-down bark and solid wood chunks produced in the manufacturing of wood products and normally used as fuel.

Hold Down

A type of iron clamp, fitting into a hole in a bench; tightened or loosened by hammer taps.

Holding Wood

When felling timber, this is the part of a tree left uncut until the end in order to hold the fall of the tree in the desired direction.

Hollow Grinding

A concave bevel on a chisel, gouge, or knife.

  • Cream-white heartwood
  • Irregular grain but fine texture
  • Difficult to saw because of the irregular grain
  • Nails, screws, and glues satisfactorily
  • Used as a substitute for boxwood and dyed as a substitute for ebony; small musical instruments, keys for pianos and organs, and marquetry.
Honduran Rosewood
  • Heartwood varies from pinkish to purple-brown with black markings
  • Straight to slightly wavy grain
  • Medium to fine texture
  • Rather difficult to work with
  • Used for finger boards for banjos, guitars, and mandolins; piano legs, picture frames, furniture, and billiard tables

A tooth form that has evenly spaced teeth, wide gullets, and a positive rake angle.

Hot Logging

Logging system operation in which the logs are not stored or decked, but loaded onto a truck as soon as they are skidded to a landing.

Horizontal Boring

An alternative to mortise and tenon joint; has two drilling heads, side by side and usually an adjustable table for height.

Horned Dado

This is caused by the outside blades of a stacked dado head cutting deeper than the chipper blades.


The shallow mortise or cavity for receiving the major part of a time end, generally copied with a smaller deep mortise to receive a tenon tying the joint together.

Hundred Lineal Feet (CLF)

A term used to indicate unit of measurement.

Hundredweight (CWT)

A unit of weight, used by carriers as a basis to measure freight rates on lumber shipments.

Hydraulic Barking

Removal of bark from round timber, such as bolts, logs, or billets, by high-pressure jets of water as the pieces are mechanically rotated in a closed chamber.

Hydrogen Bond

An intermolecular attraction force that results when the hydrogen of one molecule and a pair of unshared electrons on an electronegative atom of another molecule are attracted to one another.


Having a strong tendency to bind or absorb water.


Having a strong tendency to repel water.


The tendency of wood to absorb and expel moisture as humidity levels change.

Lumber Glossary Term Definition

A beam whose cross section resembles the letter “I”. One in which the top and bottom flanges (such as 2x4s) are connected by thinner material (such as OSB or plywood).


Incense Cedar

Idle Time

Scheduled non-operating time.

Idler Wheel

In band sawing, it is the unpowered half of the pulley-like system that turns the blade. Its primary purpose is to guide the blade.

  • Yellow-olive heartwood
  • Variegated streaks and stripes
  • Usually straight grain, often wavy or curly
  • Fine and even growth rings
  • Fine to medium texture
  • Moderately stable, fairly hard and heavy
  • Works easy with both hand and machine tools
  • Used for high-class furniture, cabinet making, high-grade flooring, paneling and gunstocks.
Imperfect Manufacture

Includes all defects or blemishes produced in manufacturing.


Wood in which the cell walls have been impregnated with synthetic resin so as to reduce materially its swelling and shrinking.


Inch or inches.

Incipient Decay

An early stage of decay in which hyphae have invaded the cell structure, sometimes discoloring the wood, but have not perceptibly reduced the hardness of the wood.

Incised Wood

Wood with slots cut into the side of the wood so that preservative chemicals can penetrate more deeply during pressure treatment. Western species of wood don’t absorb preservative chemicals as easily as some woods and require incising so that enough of the preservative enters the wood.

Included Sapwood

Areas of light-colored wood, apparently sapwood, found within the portion of stem that has becomes heartwood.

Increment Borer

A tool used to take a small core from the bole of a tree to determine growth rate.



Industrial (IND)

A term for lumber destined for remanufacture such as industrial clears, moulding stock and shop.


One who logs and sells his output on the open market; not associated with a mill or under a company/dealer contract.

Industrial Wood

All round wood products excluding fuel wood.


The direction a work piece is fed into a blade or cutter.


Covers the practice of inletting any one material into another material of different color or composition.

Inorganic-Bonded Composites

Manufactured wood-based composites where an inorganic binder, typically gypsum or magnesia-cement, acts as a continuous matrix and fully encapsulates the wood elements.

Internal Stresses

Stresses that exist within an adhesive joint even in the absence of applied external forces.


In wood bonding, a region of finite thickness as a gradient between the bulk adherent and bulk adhesive in which the adhesive penetrates and alters the adherents properties and in which the presence of the adherent influences the chemical and/or physical properties of the adhesive.


To expand with heat to provide a low-density film; used in reference to certain fire-retardant coatings.


An exotic hardwood of South America; renowned for its attractive color, density and rigidity.

  • Olive-brown heartwood
  • Straight to irregular grain
  • Low to medium luster
  • Very high strength
  • Resistant to wood bending
  • Difficult to work with
  • Ideal for bridge building, naval construction, decking, exterior construction, factory flooring, tool handles, archery bows, walking sticks and fishing rods.

An area of a deck that has been cut out to accommodate landscape elements such as trees.


This process uses separate inlays of wood, ivory, bone, brass, silver, etc., cut to shape, laid on the ground, the outlines traced with a fine point and the appropriate recesses cut in with wood-craving tools.

Integrated Logging

Logging operation that segregates and delivers a variety of products to mills and processors that will use them to their greatest potential.

Intensive Forest Management

Utilization of a wide variety of silvicultural practices, such as planting, thinning, fertilization, harvesting, and genetic improvement to increase the capability of the forest to produce fiber.

Intergrown Knot

One partially or completely Intergrown on one or two faces with the growth rings of the surrounding wood.

Interim Forest

A forest that exists or will exist until conversion to a target forest is complete. An interim forest may develop under intensive forest management and may be excellent stocking, but it does not necessarily represent the forest desired at some future time. This is also known as transition forest.

Interlocking Yarder

Device that allows the main and haul-back drums to be operated together as a single unit to maintain running line tension.

Intermediate Support Spar tree or cable sling located between the head spar and tail spar to which a tree jack is attached to support a multispan skyline.
Intermediate Trees

Trees with small, crowded crowns below, but extending into the general canopy level; these trees receive little light from above and none from the side.

International Log Rule

A formula rule that allows a 1/2 inch taper from each 4 feet of length and allows for 1/16-inch shrinkage for each inch of board thickness. This rule is used by the USDA Forest Service.

International 1/4-inch Scale

A log scale modification of an earlier rule using a 1/8-inch kerf, based on an analysis of the loss of wood fiber incurred in the conversion of saw logs to lumber. This is one of the few rules that incorporates a basis for dealing with log taper.


A tree relatively incapable of developing and growing normally in the shade of, and in competition with, other trees.

  • Golden-orange to brown in color
  • Interlocked grain
  • Rather coarse texture, but even
  • Medium density
  • Medium bending and crushing strength
  • Very low stiffness
  • Resistance to shock loads
  • Works satisfactorily with hand and machine tools
  • Used for ship and boat building, laboratory benches, furniture, and domestic flooring.

Exhibiting the same properties in all directions.


Idaho White Pine

Lumber Glossary Term Definition

Joists and Planks


A device used for suspending a loading-line lead block from a skyline.


An unskilled example or display of logging work. Contemptuous expression applied to an unskilled piece of work in logging, particularly in felling, where several trees are lodged and/or crisscrossed.


A lightweight, two-drum yarder usually on a truck with a spar and boom; may be used for both short distance yarding and loading. Frame mounted on a sled or vehicle for loading logs.

Jammer Logging Cable logging system generally restricted to one skidding line and used for winching logs up to 300 feet from the cutting area to a log collection point.
Janka Test

A hardness test, usually for wood flooring, the rating is pounds of pressure required to press a steel ball .444 inches in diameter one half way into the wood.


A device used to make special cuts, guide a tool, or aid in woodworking operations.

Jig Saw

A power tool that cuts by moving a blade up and down as it is guided through the cut.


A machine to true the edges of boards usually in preparation for gluing.

  • Adhesive Joint – The location at which two adherents are held together with a layer of adhesive.
  • Assembly Joint – Joints between variously shapes parts or subassemblies such as in wood furniture.
  • Butt Joint – An end joint formed by abutting the squared ends of two pieces.
  • Edge Joint – A joint made by nodding two pieces of wood together edge to edge, commonly by gluing. The joints may be made by gluing two squared edges as in a plain edge joint or by using machined joints of various kinds.
  • End Joint – A joint made by bonding two pieces of wood together, end to end, commonly by finger or scarf joint.
  • Fingerjoint – An end joint made up of several meshing wedges or fingers of wood bonded together with an adhesive. Fingers are sloped and may be cut parallel to either the wide or narrow face of the piece.
  • Lap Joint – A joint made by placing one member partly over another and bonding the overlapped portions.
  • Scarf Joint – An end joint formed by joining with adhesive the ends of two pieces that have been tapered or beveled to form sloping plane surfaces, usually to a featheredge, and with the same slope of the plane with respect to the length in both pieces.
  • Starved Joint – A glue joint that is poorly bonded because an insufficient quantity of adhesive remained in the joint.
  • Sunken Joint – Depression in wood surface at a joint caused by surfacing material too soon after bonding.

The craft of connecting and securing the separate members of the timber frame to one another by means of specific cuts on the ends and/or sides of the timbers.


Part or the arrangement of the part, where two or more timbers are joined together.

Jointed (JTD)

In lumber manufacture, finger-jointing is most common although sometimes other types of joints may be used.


A piece of lumber two to four inches thick and six inches wide, used horizontally as a support for a ceiling or floor. Also, such a support can be made from aluminum, steel, or other materials.

Joists and Planks (J&P)

The national grading rules contain four grades of structural joists and planks; select structural, No. 1, No. 2, and No. 3. Nominal sizes are 2 to 4 inches thick by 5 inches and wider. The abbreviation (J&P) in generally used to indicate a specific section in the grading rules under which the lumber was graded.


One who logs and sells his output on the open market; not associated with a mill or under a company/dealer contract.

Joist Hanger

A pre-manufactured metal piece typically attached to a ledger or to beam to support a joist. Joist hangers should be galvanized.


A hydraulic control lever that can be operated in up to four directions, controlling a number of functions through one hydraulic valve.



Juvenile Wood

The wood in every tree that forms within its first 10 years or so; usually has undesirable characteristics such as low strength and shrinkage along the grain.

Lumber Glossary Term Definition

Kiln Dried


The groove left in a board when cut by a saw blade.

KG Blade

The blade on a crawler used to clear unwanted vegetation in preparation for planting tree seedlings.


When a work-piece is thrown back in the opposite direction the cutter is turning.

Kiln In lumber drying, a kiln is a room or building where air circulation, moisture, and temperature are controlled to dry wood.
Kiln Dried

Lumber that has been dried in a kiln (See Kiln).

King Post

A central, vertical post extending from the bent plate or girt to the junction of the rafters at roof peak.

  • Variegated colors of rich violet-brown to almost black
  • Usually straight grained
  • Uniformly fine textured
  • Works well with hand and machine tools
  • Used for inlays, marquetry, oyster veneering and bandings.

A form of warp characterized by abrupt deviation from straightness or flatness due to either localized grain distortion (as around knots) or to deformation by misplaced stickers.


Unit of weight or force equivalent to 1,000 pounds.

Knee Brace

A short diagonal timber placed between the horizontal and vertical members of the frame to make them rigid.


A design feature that allows a piece of furniture to be easily disassembled by the use of special hardware or joinery.


A branch or limb embedded in a tree and cut through in the process of manufacturing. Knots are classified according to occurrence, quality, and size. In lumber, the size classifications are: Pin knot, one not over ½-inch in diameter; Small, a knot larger then ½-inch but not over ¾-inch; Medium, larger then ¾-inch but not over 1 ½-inch; Large, over 1 ½-inch in diameter.

  • Encased Knot – A knot whose rings of annual growth are not intergrown with those of the surrounding wood.
  • Intergrown Knot – A knot whose rings of annual growth are completely intergrown with those of the surrounding wood.
  • Loose Knot – A knot that is not held firmly in place by growth or position and that cannot be relied upon to remain in place.
  • Pin Knot – A knot that is not more than ½ inch in diameter.
  • Sound Knot – A knot that is solid across its face, at least as hard as the surrounding wood, and shows no indication of decay.
  • Spike Knot – A knot cut approximately parallel to its long axis so that the exposed section is definitely elongated.
Knot Cluster

Two or more knots grouped together as a unit with the fibers in the wood deflected around the entire unit.


Hydraulically operated loading boom whose mechanical action imitates the human arm.

Kraft Paper

Comparatively coarse paper particularly noted for its strength; unbleached grades are used primarily as a wrapping or packaging material.

Lumber Glossary Term Definition



When some woods are quarter-swan, a mottled effect is revealed in the section through the medullar rays. In some woods, like maple and elm, the effect is very subtle, but in others it is regular and distinctive. The classic examples are European or London place (Platanus acerifolia) and Roupala (Roupala brasiliensis). These species are often referred to as lacewood.


A finish; a clear varnish.

Lag Screw

A large screw, usually 4 inches or longer, with a hex head, tuned with a wrench.

Laminate A thin, plastic material used to cover a board. The most common use of laminate is for counter and table tops. It is often referred to by the brand name Formica ®.
Laminated Wood

A “piece” of wood built up of plies or layers that have been joined; either with glue or mechanical fastenings. The term is most frequently applied where the plies are too thick to be classified as veneer and when the grain of all plies is parallel.

Laminated Veneer Lumber (LVL)

Structural wood members constructed of veneers laminated to make a “flitch” from which pieces of specific sizes can be trimmed.

Land Base

Acres of forest land that are actually available for forest management. This involves future trends not only in forest growth but also in deletions from the land base.

Land Classifications
  • Basal Area Jam Acre – Land class based on total area per acre.
  • Site Class – Classification of forest land in terms of its inherent capacity to grow crops of industrial wood. Expressed in cubic-foot growth per acre per year.
  • Site Index – Expression of the growing potential of a specific forest site based on the height of a free-growing dominant or co-dominant tree of a representative species in a forest of the same type at a specified age.
  • Stand Age – Age of trees of the dominant forest type and stand-size class.

A cleared area in the woods to which logs are yarded for loading onto trucks for shipment to a processing plant. This is also known as brow, deck, dock, or ramp.

Land-Use Classes
  • Gross Area – Entire area of land and water as determined by the Bureau of Census.
  • Forest Land – Land at least 16.7% stocked by forest trees of any size, or formerly having such tree cover, and not currently developed for non-forest use.
  • Commercial Forest Land – Forest land capable of producing crops of industrial wood and not withdrawn from timber utilization by statue or administrative regulation. Included are areas suitable for growing crops of industrial wood and generally capable of producing in excess of 25 cubic feet per acre of annual growth.
  • Non-Commercial Forest Land – Unproductive forest land incapable of yielding crops of industrial wood because of adverse site conditions. Also, productive forest land withdrawn from commercial time use through statue, administrative regulation, or exclusively used for Christmas tree production.
  • Reserve Forest Land – Noncommercial forests that are productive but reserved for recreation of other non-timber uses.
  • Land Area – Area of dry land and land temporarily or partially covered by water such as marshes, flood plains, streams, sloughs, and estuaries. Canals less then 1/8 mile wide, lakes reservoirs, and ponds smaller then 40 acres are included as land area.
  • Non-Forest Land – Land that has never supported forests. Land formerly forested where forest use is precluded by development for non-forest uses, such as cropland, improved pasture, residential areas, and city parks.

A thin, narrow wooden strip, used as a backing for wall plaster or other materials.

Latewood (Summer Wood)

The part of a trees annual growth ring that is formed later in the season.

Latex Paint

A paint containing pigments and a stable water suspension of synthetic resins that forms an opaque film through coalescence of the resin during water evaporation and subsequent curing.

Lathe Checks

In rotary cut and sliced veneer, the fractures or checks that develop along the grain of the veneer as the knife peels veneer from the log. The knife side of the veneer where checks occur is called the loose side. The opposite and log side of the veneer where checking usually does not occur is called the tight side.


A framework of crossed wood made of laths or other thin pieces of wood. Lattice often can be bought pre-made in 4×8 sheets.




Less than Carload

Leave Strip

A strip of uncut timber left between cutting units or adjacent to another resource such as a stream. This is also known as a buffer strip, green strip, or streamside management zone.


A length of a board that is horizontally attached to the side of a house and holds up one edge of a deck.

Less than Carload (LCL)

This term indicates that a railcar is not loaded full, nor does it meet minimum requirements as prescribed by railed tariffs.


An instrument for asserting whether a surface is horizontal, vertical, or at a 45 degree angle; essentially consists of an encased, liquid-filled tube containing an air bubble that moves to a center window when an instrument is set on an even plane.


Light Framing

LFVC Loaded fullvisible capacity



Length LIN (Lineal)

Light Framing (LF)

The national grading rules contains three grades of light framing; construction, standard and utility. Nominal sizes are 2 to 4 inches thick and 2 to 4 inches wide. The abbreviation (LF) is used to indicate a specific section in the grading rules under which the lumber was graded.

Light Sap Stain

A slight difference in color which will not materially impair the appearance of a piece if given a natural finish.


A complex chemical substance making up approximately 25% of wood substance; interspersed with cellulose in forming the cell wall. Lignin stiffens the cell and functions as a bonding agent between cells; the second most abundant constituent of wood, located in the secondary wall and the middle lamella.


The part of the tree above the stump that does not meet the requirement for saw logs or upper stem portions. Includes all live, sound branches to a 4-inch outside back diameter minimum.


A sedimentary rock composed largely to minerals calcite, and/or aragonite, which are different crystal forms of calcium.

Lineal (LIN) A term referring to length; lineal footage is the total length in feet of a piece or of all pieces of the same width in a shipment. It is used largely for specialty itmes such as mouldings and millwork.
Linear Foot

A measurement of the length of a board (i.e. – Three 8-foot-long 2x4s and four 6-foot-long 2x4s both would be described as 24 linear feet of 2x4s).

Line Level

A level that hangs from a mason’s line; typically used to transfer level elevations from one post to another.

Linseed Oil

This is an amber-colored, fatty oil extracted form the cotyledon and inner coats of the linseed. The raw oil extracted from the seeds by hydraulic pressure is pale in color and practically without taste or order. When boiled or extracted by application of heat and pressure, it is darker, has a bitter taste and an unpleasant odor.

Live Load

The amount of weight any structure is designed to support. Most deck designs call for a live load of 60 pounds per square foot.

LNG Lining
Load Area

The area found by multiplying the beam spacing by the post spacing to determine the post thickness required by building codes.

Loaded to Full Visible Capacity (LFVC)

A railroad term to accord light weight lumber shipments the same freight rate consideration as heavier species on higher carload minimum weights. If a car is loaded full, shipper obtains benefit of lowest rate even though minimum weight requirements for lowest rate haven’t been met.

Loading Jack

Rigging suspended from a spar tree guy line immediately above the line of haul and terminating in a loading block.

Lock Set

A door lock.


8-foot or longer tree segment.

Log Deck

A pile of logs on a wood landing or in a mill yard.


A person employed in the production of logs and/or wood from standing timber, also known as a Lumberjack.

Logging Plan

Used in the eastern and western regions: layout, on a topographical map, of roads, landings, and setting boundaries of a logging area.

Logging Residues

Unused portions of pole timber and saw timber trees killed by land clearing, cultural operations, or timber harvesting.

Logging Setting

An area to be logged; a block or strip.

Logging Truck

A vehicle used to transport logs. A logging truck consists of a cob, containing the engine and a place for the driver to sit, and a trailer on which logs are placed. The trailer usually has an adjustable carriage in order to accommodate loads of various lengths.

Log Jack

A tool used to raise a log from the ground during bucking. Similar to a peavey, but with a flattened steel loop on the underside so when the hook fastens into a log on the ground and the handle is lowered, the log is jacked up and remains elevated.

Log Rule

A table intended to show the amounts of lumber that may be sawn from logs of different sizes under various assumed conditions.

Log Scale

Measure of the volume of wood in log/logs, usually expressed in board feet and based on various log scaling rules.

London Dispersion Forces

Intermolecular attraction forces between non-polar molecules that result when instantaneous dipoles induce matching dipoles in neighboring molecules.

Long Butt

A section cut from the bottom log of a tree and culled because of rot and other defects.

Long-Line Skidding

At term currently synonymous with skyline skidding.


Parallel to the direction of the wood fibers.

Long-Span Skidding

A cable system capable of skidding logs for 3,000 feet or more.


Pulpwood 120 inches or more in length.

Longwood Harvesting

A timber harvesting method in which harvested trees are moved to the landing either as whole trees or as topped and limbed tree-length logs. At the landing, further processing such a limbing, topping, bucking, chipping, or loading is carried out as necessary.

Loose Knot

A knot not held in place by growth, shape or position.

Loosened or Raised Grain

Consists of a small portion of the wood being loosened or raised but not displaced.

Low Voltage Lighting

Commercially available lighting systems that use a transformer to reduce the needed electrical current. These lighting systems are designed for do-it-yourself applications.


Lodgepole Pine


Logs which have been sawn, planed, and cut to length; a manufacture product derived from a log in a saw mill, or in a sawmill and planing mill. Which when rough shall have been sawed, edged and trimmed at least to the extent of showing saw marks in the wood on the four longitudinal surfaces of each piece for its overall length, and which has not been further manufactured other than by cross-cutting, ripping, resawing, joining crosswise and/or endwise in a flat plane, surfacing with or without end matching and working.

  • Factory and Shop Lumber – Lumber intended to be cut up for use in further manufacture. It is graded on the percentage of the area that will produce a limited number of cuttings of a specified minimum size and quality.
  • Matched Lumber – Lumber that is edge dressed and shaped to make a close tongued-and-grooved joint at the edges or ends when laid edge to edge or end to end.
  • Nominal Size – As applied to lumber, the size by which it is known and sold in the market, often differs from the actual size.
  • Patterned Lumber – Lumber that is shaped to a pattern or to a molded form in addition to being dressed, matched, or shiplapped, or any combination of these workings.
  • Rough Lumber – Lumber that has not been surfaced but has been sawed, edged, and trimmed.
  • Shiplapped Lumber – Lumber that is edge dressed to make a lapped joint.
  • Side Lumber – A board from the outer portion of the log; originally one produced when squaring off a log for a tie or timber.
  • • Structural Lumber – Lumber that is intended for use where allowable properties are required. The grading of structural lumber is based on the strength or stiffness of the piece as related to anticipated uses.
  • Surfaced Lumber – Lumber that is dressed by running it through a planer.
  • Yard Lumber – Lumber of all sizes and patterns that is intended for general building purposes having no design property requirements.
Lumber for Dimension

The National Dimension Manufacturers Associated defines both hardwood and softwood dimension components as being cut to a specific size from kiln-dried rough lumber, cants, or logs.

Lumber Tally

A record of lumber giving the number of boards or pieces by width, thickness, length, grade and species.

Lumber-Core Plywood

Plywood where thin sheets of veneer are glued to a core of narrow boards. Lumber-core plywood differs from regular plywood in that regular plywood is made up of successive layers of alternating grain veneer.


One who works in forest performing a variety of jobs related to the harvesting of timber; most commonly used in the Northeastern United States and eastern Canada. Also known as a logger.

Lumber Ruler

A tool resembling a ruler with a handle at one end and a hood at the other which is used to calculate the board footage of a piece of lumber.

Lumber Tally

Record of lumber giving the number of boards or pieces by size, grade, and species; often expressed in MBF.


The cell cavity in wood anatomy.

Lumber Glossary Term Definition


Macassar Ebony
  • Dark brown to black heartwood
  • Mostly straight grain by may sometimes be irregular or wavy
  • Fine and even texture
  • Exceptionally heavy, dense wood
  • Hard to work with hand or machine tools
  • Pre-boring is necessary for nailing
  • Used for cabinet work, walking sticks, musical instruments, billiard cues, and decorative veneers.

The relative ease with which a metal can be shaped by various cutting processes.

Machine Bolt

A bolt typically configured with a hex head, a nut and a blunt end. It is meant to hold two pieces, usually the support structure by pinning them together; the threads hold only the nut and don’t screw into the wood itself.

Machine Burn Burn marks on the surface of converted wood as a result of poor sawing or machining.
Machine Rate

Cost per unit of time for owning and operating a logging machine or some logging equipment. In accordance with engineering practices, the rate is composed of fixed costs such as depreciation, interest, taxes, and license free, and variable costs including fuel, lubricants, and repairs and replacement of components such as tries and wire rope.

Machine Time
  • Machine Availability – Machine availability is expressed as a percent of the scheduled operating time during which a machine is not under repair or service. In other words, it is the percentage of the scheduled operating time during which the machine is mechanically fit and is itself capable of doing productive work. It is expressed by scheduled operating time minus mechanical delay time divided by schedule operating time and multiplied by 100.
  • Machine Down-Time – Time during which a machine cannot be operating in production or auxiliary work because of breakdown, maintenance requirements, or power failure.
  • Machine Utilization – Machine utilization is expressed as a percentage of the scheduled operating time that is productive time. It is computed by productive time divided by scheduled operating time and multiplied by 100.
  • Scheduled Non-Operating Time – Time when no production is scheduled for a machine.
  • Idle Time – Scheduled non-operating time during which a machine is not working, moving, under repair, or being serviced.
  • Out-Of-Shift Repair Time – Part of non-operating time during which a machine is actually undergoing repair. Waiting time is not included here as in the in-shift repair time element.
  • Out-Of-Shift Service Time – Part of non-operating time when a machine is actually undergoing service time. This does not include waiting time.
  • Scheduled Operating Time – Time when a machine is scheduled to do productive work. Time during which a machine is on standby as a replacement machine is not considered as scheduled operating time. When a machine is replaced, the scheduled operating time of the replaced machine is considered as ending when the replacement arrives on the job. Scheduled operating time of the replacement commences when it starts to move to the location of the machine it is replacing. Extension of the regular shift operation into overtime is considered as scheduled operating time.
  • Operating Time – Time during this period can be either productive or delay time. Delay time is the sum of disturbance time, service time, and repair time.
  • Mechanical Delay Time – Part of scheduled operating time spent in repair or service during which a machine cannot work. It does not include replacement of oil filters and spark plugs as scheduled in a preventative maintenance program. Servicing is fueling, lubricating, and doing the work specified in a scheduled preventative maintenance program. When a machine is being serviced while under repair, the time involved is to be classified as repair time, not service time. Repair and service time occur in both scheduled operating and non-operating time.
  • In-Shift Repair Time – Part of mechanical delay time when a machine is actually undergoing repair plus the time during which a machine is waiting to be repaired or for repair parts, mechanics, or facilities. This is the same as repair time.
  • Active Repair Time – Time during which actual repair work is being carried out on the machine itself or a dismantled part of the machine.
  • Repair Time – Sum of active repair time, waiting repair time, and time spent servicing the machine while undergoing repair.
  • Waiting Repair Time – Time during which the machine is waiting for a mechanic, spare parts, or repair equipment. This includes time for transporting the machine to and from the workshop.
  • In-Shift Service Time – Part of mechanical delay time when machine is actually undergoing service plus the time a machine is waiting for service parts, mechanics, or repair facilities. This is the same as service time.
  • Service Time – Time for normal service and maintenance.
  • Non-Mechanical Delay Time – Part of scheduled operating time during which a machine is not doing productive work for reasons other then repair or service. This time may be subdivided by causes; weather or terrain conditions, waiting for another phase of an integrated operation, assisting other machines, and operator talking with visitors.
  • Disturbance Time – Examples are: time spent for logging down, towing, detail planning, talking to supervisor, waiting for wood, and waiting for better weather.
  • In-Shift Moving Time – The part of non-mechanical delay time during which a machine is moving or being transported. Includes the time taking to move or transport the machine between operating sites or between camp and site, assuming the machine is not under repair service. It does not include time spent moving between adjacent working positions on any one site.
  • Operational Lost Time – Time during which production is halted due to things such as operating conditions, non-availability of auxiliary equipment, or using the machine in a non-productive manner to assist other machines.
  • Personnel Time – Part of non-mechanical delay time in which a machine lacks an operator or any other member of the machine crew.
  • P.M.H. – Productive Machine Hour
  • Productive Time – Part of scheduled operating time in which a machine is performing a function for which it was scheduled. Also, time spent in carrying out the task; the sum of actual productive and other productive time.
  • Actual Productive Time – Time spent using the machine to carry out the actual task.
  • Other Productive Time – Time when the machine is carrying out tasks other than those for which are intended.
  • S.M.H. – Scheduled Machine Hour
  • Total Time – Total elapsed time for the period under consideration; total time for a period of 1 week is 168 hours (7 days multiplied by 24 hours per day).
Machine Stress-Rated (MSR Lumber)

Lumber that has been evaluated by mechanical stress rating equipment; each piece is nondestructively tested and marked to indicate the modulus of elasticity. MSR lumber is also required to meet certain visual requirements.

Mahogany An expensive, pink to dark reddish brown hardwood. It is a tropical tree of the genus Swietenia.
Main Line

In cable yarding, the line used to bring logs to the landing.

Main Line Block Block on a spar through which the main line runs.
Main Road

Road that supports a high level of traffic, usually well built and well designed.

  • Pick-red to blood red and red-brown heartwood
  • Straight grain
  • Lustrous and uniform texture
  • Tends to split in nailing, holds screws well
  • Used for furniture, cabinets, turnery, high-class joinery, interior fittings, laboratory benches, boat building and marine plywood.

A tool like hammer with a wooden, rawhide or rubber head.

Managed Harvest

Estimated volume of timber on commercial forest land that could be cut annually for the next ten years while improving tree stocking and bringing about a more even distribution and age classes. Annual managed harvest is considered separate from harvest cuttings and thinnings and is determined by a computer using an area control system that specifies the number of acres to be cut annually.

Managed-Volume Inventory

Computation of pertinent data, such as volume or basal area and increment and mortality of stands, to assess silvicultural opportunities.


Unit of work preformed by one man in one hour.


The producing sawmill sawing lumber from logs.

Manufacturer’s Agent

A sales representative for a particular sawmill or several non-competitive lumber manufacturers.

Manufacturing Defects

Includes all defects or blemishes that are produced in manufacturing, such as chipped grain, loosened grain, raised grain, torn grain, shkips in dressing, hot and miss, variation in sawing, mis-cut lumber, machine burn, machine gouge, mismatching, and insufficient tongue and groove.


To select and indicate, usually with paint, trees to be felled in a logging operation and to be left may also be marked.


Selecting and indicating, by a blaze or paint spot, the trees to be cut or left in a timber cutting operation.

Marlin Spike

Iron tool that tapers to a point. This is used to separate strands of rope.

Mason’s Line A string that does not stretch, making it useful to establish horizontal lines when laying out the various heights of a deck.

A material with adhesive properties, usually used in relatively thick sections, which can be readily applied by extraction, trowel, or spatula.


A temporary roadway constructed of hardwood lumber.

Mature Timber

A stand of trees that has attained an age or size that satisfies the primary economic goal for which it is managed.


Thousand Board Feet.


Thousand (ft.) board measure.


Moisture Content.


Medium density fiberboard, very stable underlay for counter tops etc. to be covered with laminate.

Mean Annual Increment (MAI) Total increment growth up to a given age divided by that age.
Meandering Line

Survey line at the high-water mark on navigable lakes and streams. This line is where continuous vegetation ends and muddy or sandy shore beings.


The process of dividing the merchantable tree stem into segments of specified length for the purpose of bucking. Measuring a stand begins when a worker begins dividing the first tree into desired lengths and ends when the last tree has been measured.

Measuring Tape

A tape of cloth, paper, plastic, or steel marked off in a linear scale, as of inches or centimeters, for taking measurements.

Mechanical Adhesion

Adhesion between surfaces in which the adhesive holds the parts together by interlocking action.

Mechanical Delay Time Cutting with mechanized equipment, such as the carrier-mounted shear of feller-buncher, instead of by hand with a power saw.
Mechanized Logging

Logging in which most or all of the hand labor is replaced by machines; requires a large outlay of capital.

Medium Density Fiberboard (MDF)

A special type of tempered hardboard characterized by a very fine, smooth finish. MDF is used in cabinet making.

Medium Grain

Wood with 4 to 6 rings per inch.


In forestry, the measurement of both standing and harvested timber.



Merchantable Top

Smallest utilizable top.

Merch Top

Merchantable Top


A tissue capable of active cell division, thereby adding new cells to the plant body.

Metric Tons

Unit of weight equal to 1,000 kilograms. Approximately 2,205 pounds.

Mexican Bocote
  • Heartwood is a dull golden brown with variegated irregular markings
  • Straight grained
  • Medium-coarse texture
  • Works easily with both hand and power tools
  • Moderately durable
  • Resistant to preservatives
  • Used for cabinets, furniture, decorative boxes, boat decking, vehicle bodies, and light construction

Mixed Grain


An extremely narrow bevel along a cutting edge, which increases the sharpness angle for greater edge durability.

Mill Run

Lumber that is in varying grades and widths.


Planed and patterned lumber for finish work in buildings, including items such as sash, doors, cornices, panel work, and other items of interior or exterior trim. This does not include flooring, ceilings, or siding.

Milk Pain

Paint made with milk solids, chemically akin to casein glue, often the original finish on antique furniture.

Mineral Streak

An olive to green-black or brown discoloration of undetermined cause in hardwoods.

Miter-And-Spline Joint

A joint with two mitered surfaces connected by a spline.

Miter Box

An apparatus to guide a saw to make miter joints.

Miter Gauge

A tool that slides into a slot on a power tool such as a table saw, router table, band saw, etc. A miter gauge can be adjusted to different angels and is used to slide the stock past the blade.

Miter Joint

Pieces that are cut on an angle to make a joint.

Mismatched Material

Worked material that does not fit tightly at all points of contact between adjoining pieces or in which the surfaces or adjoining pieces are not in the same plane.

Mixed Car

A railroad car loaded with various kinds, sizes and/or species of lumber.

Mixed Grain

Lumber may be both vertical and flat grain.




Capable of being moved from one location to another.


Theoretical abstraction, usually capable of mathematical manipulation, used to evaluate a problem or a subject of interest.

Modified Wood

Wood processed by chemical treatment, compression, or other means to impart properties quite different from those of the original wood.

Modular Housing

A type of housing in which major components are assembled in a factory and then shipped to the building site to be joined with other components to form the finished structure. The components are usually uniform incremental sizes; permitting some flexibility of design while maintaining the structure of individual elements. Sometimes called “prefabricated’ or “prefab” housing by laymen; these terms are avoided by the industry because of negative connotations.

Modulus of Elasticity (MOE)

The relationship between the amount a piece deflects and the load causing the deflection determines its stiffness.

Moisture Content (MC)

A measure of the amount of water in a piece of lumber.

Molding (Moulding)

A strip of material with a profile cut on the facing edges, used for trimming.

Molecular Weight

The sum of the atomic weights of the atoms in a molecule.


Circle of twisted strands of wire rope used as a temporary line to connect the eye splices of two lines.

Monkey Wrench

A half tool with adjustable jaws for turning nuts of varying sizes.

Mopping Up

Act of making a fire safe after it has been controlled by extinguishing or removing burning material along or near a control line.


Modulus of Rupture

Morse Taper

The standard for the taper on the shanks of drill chucks, drill bits and lathe centers. The different size tapers are designated by numbers, #1 being the smallest, #3 is common for drill chucks.


A rectangular hole cut into a piece of wood to accept a tenon.

Mortise and Tenon

Any joint consisting of a projection (tenon) on the end of one timber and a corresponding slot (mortise) on the other.


Number or sound wood volume of healthy trees that have died from natural causes during a specified period.


A term used to describe various figuring effects, from subtle lacewood to a more velvety figuring.

Moulding (MLDG)

Small shaped lengths of wood used for both interior and exterior trim.

Moulding Stock

Developed in the making of other standard grades; each piece is graded on the basis of the percentage of the area suitable for ripping into strips of a given minimum size and quality.


Machine Stress Rated


Malaysian Timber Certification Council.

Multilevel Deck

A deck that has several discrete areas at different levels. The different levels often are built to conform to a sloping terrain or make a transition from a second story to a ground level.

Multiple Entry

A deck that has several discrete areas at different levels. The different levels often are built to conform to a sloping terrain or make a transition from a second story to a ground level.


Practice of forestry that combines two or more objectives.

Multiple-Use Forestry

Concept of forest management that combines two or more objectives, such as production of wood or wood-derivative products, forage and brown for domestic livestock, proper environmental conditions for wildlife, landscape effects, protection against floods and erosion, recreation, and protection of water supplies.

Multiple-Use Management

Management of land resources with the objective of achieving optimum yields of products and services from a given area without impairing the productive capacity of the site.

Multispan Skyline

A skyline having one or more intermediate supports.


An operation handling two or more stems at the same time.


A strip of metal or wood separating and holding panes of glass in a window or door.


Tract of partly forested peat-land supporting mosses, shrubby plants, and scattered trees.

Lumber Glossary Term Definition

Nose One Edge

Nail Gun A mechanical device for driving nails into an object by the force of compressed air.
Nail Set

A short shaft of metal with a narrow blunt point used to set nails below the surface of wood by placing the blunt end on the nail head and striking the other end with a hammer.

Nail Staining

Caused when the metal bleeds around the nail hole.

Machine Burn Burn marks on the surface of converted wood as a result of poor sawing or machining.
Nanoindentation Hardness

A hardness measurement conducted at the nanometer scale. Nanoindentation hardness uses an extremely small indenter of a hard material and specified shape to press into the surface of a specimen with sufficient force to cause deformation.

Natural Regeneration Renewal of a forest achieved either by natural seeding or from the vegetative reproduction of plants on the site.
Naval Stores

A term applied to the oils, resins, tars and pitches derived from oleoresin contained in, exuded by, or extracted from tress chiefly of pine species or from the wood of such trees.

NBM Net Board Measure
Main Line

In cable yarding, the line used to bring logs to the landing.

Net Annual Growth Increase in volume of trees during a specified year. Components of new annual growth include the increment of net volume of trees at the beginning of the specified year that survive to the years end, plus the net volume of trees reaching the minimum size class during the year, minus the volume of trees that died during the year, and minus the net volume of trees that become rough or rotten trees during the year.
Net Board Measure

Content of lumber when calculated from measurements of actual dimensions, including tongue or lap.

Net Scale Actual amount of merchantable wood contained in a log as opposed to the gross scale, which includes defects.
Nominal Size

The rough-sawn size of a piece of lumber. When purchasing planed lumber, it is sold by its nominal, rough sawn size. Usually expressed in terms of the nearest inch regardless of actual surface, or net sizes (i.e. – 2×4 is the name for a rough cut piece of about 2×4 inches. It is then finished by planning and sometimes sanding it down to its actual dimensions).

Non-Commercial Species

A tree species in which small size, poor form, or inferior quality is typical. These species do not normally develop into trees suitable for conventional forest products.

Non-Piloted Bit

A router bit without a guide bearing.

Nonpressure Process

Any process of treating wood with a preservative or fire retardant where pressure is not applies.

Northern United States

Consists of the following States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont, Delaware, Maryland, New Jersey, New York, Pennsylvania, West Virginia, Michigan, Minnesota, South Dakota, Wisconsin, Illinois, Indiana, Ohio, Iowa, Kansas, Kentucky, Missouri, and Nebraska.


To make an undercut in a tree, preparatory to felling it in a given direction. This is also known as a box or an undercut.

Number One

Top-grade logs, such a number one peeler, or a number-one saw log.

Lumber Glossary Term Definition
  • Creamy-white to pale yellow
  • Moderately fine and even texture
  • Interlocked grain
  • Low bending and crushing strengths
  • Stiffness and resistance to shock loads are low
  • Extensively used where durability and strength are unimportant
Occasional Pieces Means not more than 10 percent of the pieces in a parcel or shipment.
Off-Highway Truck

A truck designed to handle loads exceeding legal highway size and weight restrictions. These trucks are not driven on highways; they are used in logging operations conducted on other types of roads.


A decorative molding profile with an “S” shape.

Oil Paint A paint containing a suspension of pigments in an organic solvent and a drying oil, modified drying oil, or synthetic polymer that forms an opaque film through a combination of solvent evaporation and curing of the oil or polymer.
Old Growth

Biologically a stand of timber that is near its climax; such trees may be 200 years or older. In timber management planning, old growth also refers to timber that is older then the rotation age planned for future forests; this definition may include trees that are 100 years or less.

Oleoresin A solution of resin in an essential oil that occurs in or exudes from many plants, especially softwoods.
On Center

A method of measuring distance between two structural members, such a joists, where you measure from the center of one member to the center of the other. It is usually abbreviated O.C.

Open Coat A piece of sandpaper with abrasive particles that are spread out to prevent clogging.

Common classification of painters for woods with large pores, such as oak, ash, chestnut, and walnut. This is also known as ‘coarse texture’.

Open-Side Carriage Skyline carriage that opens on one side allowing it to travel over intermediate support jacks.Skyline carriage that opens on one side allowing it to travel over intermediate support jacks.
Open-Top Van

A van that can be loaded from above and is often covered by a tarp or mesh.

Operational Cruise Timber inventory that includes the estimation of timber volumes or other stand information on specific geographic areas for specific purposes, as contrasted with more broadly based estimates for forest-wide planning. Inventory survey of a logging unit for developing logging plans and production budgets. Seedling surveys for regeneration stocking and pre-commercial thinning cruises for stand density are examples of operational cruises. Results from these surveys form the basis for decisions on subsequent activities about the specific geographic areas cruised.
Operations Research

A scientific approach to decision making that involves the operations of organizational systems.


Estimated volume of timber on commercial forest land that could be cut annually for the next ten years while improving tree stocking and bringing about a more even distribution and age classes. Annual managed harvest is considered separate from harvest cuttings and thinnings and is determined by a computer using an area control system that specifies the number of acres to be cut annually.

Optimum Road Spacing

The distance between parallel roads that gives the lowest combined cost of skidding and road construction costs per unit of log volume.

Orbital Sander

An electric sander that moves the abrasive in an elliptical pattern.

Oriented Strand Board (OSB)

A structural panel made of narrow strands of fiber oriented lengthwise and crosswise in layers, with a resin binder. Depending on the resin used, OSB can be suitable for exterior or interior applications.


Refers to having unique and independent properties in three mutually orthogonal planes of symmetry; longitudinal, radial, and tangential.


The side of a power tool where the board exits.


Stabilizers that are generally found on Knuckleboom loaders or mobile chippers.

Oven-Dried Weight

The weight of a piece of lumber that has been dried, under high temperatures, in an oven until it is devoid of all water. This is used to calculate the moisture content of wood.

Oven-Dry Wood

Wood completely dried until it is without any moisture content.

Overlay A thin layer of paper, plastic film, metal foil, or other materials bonded to one or both faces of panel products or to lumber to provide a protective or decorative face or a base for painting.

Point at which timber has begun to lessen in commercial value because of size, age, decay or other factors. Many trees in a virgin or old growth stand are over-matured and are, in fact, dying of old age.

Over Run

The difference between the log scale of a shipment of timber and the volume of the actual lumber obtained from it.

Over-All Dimensions

The measurements-of thickness, width, or length-of a piece of lumber which are used to compute the space occupied.


Layer of foliage in a forest canopy including the trees in a timber stand. Tall mature trees that rise above the shorter immature understory trees.

Over-Story Removal

Any silvicultural treatment with the desired end result being the removal of the over-story component from the growing stock of a multistoried stand. Examples are outright harvest, girdling, and simply felling the over-story.

Ownership Classes
  • County – Land owned/leased by counties for more then 50 years.
  • Farmer Owned – Land owned by operators of farms. A farm must include ten or more acres from which the sale of agricultural products totals $50 or more annually, or, if less than ten acres, the yield must be at least $250 annually.
  • Forest Industry – Land owned by companies or individual operating wood-using plants.
  • Indian – Tribal land held by the Federal Government but administered for Indian tribal groups and Indian trust allotments.
  • Miscellaneous Federal – Federal land other than National forest, Bureau of Land Management, and Indian land.
  • Municipal – Land owned/leased by municipalities for more then 50 years.
  • National Forest – Federal lands that have been designated by Executive Order or statue as National Forests, or purchased units and other land under the administration of the USDA Forest Service.
  • Other Public – Public land other than National Forests.
  • State – Land owned/leased by States or local public agencies for more than 50 years.

A few woods are cut into oysters, a cross-section of end grain either at right angles to the grain or at an oblique angle.

Lumber Glossary Term Definition

Posts and Timbers

PAD Partly Air Dried
Pacific Coast States

Alaska, Washington, Oregon, California, and Hawaii.


Any pigmented liquid or mastic composition designed for application to a substrate in a thin layer that converts to an opaque solid film after application.

Paint Brush A brush used for applying paint.

A portable platform used as a base for stacking, storing, and transporting goods in a unit.

Palm Nailer (Push Nailer/Brad Nailer) A palm held, spring loaded tool with a barrel for holding fine brads and pins. A fine hobby nail or brad is dropped down the barrel of the tool and the tool is then held against the wood and pushed.

Large, flat upward-curving metal plate on which log ends or pallets are placed to make skidding easier and prevents digging in and rutting.

Panel Product Any variety of wood products, such as hardboard, oriented strand board, particleboard, plywood, or waferboard, sold in sheets or panels. Although sizes vary, a standard size for most panel products is 4×8 feet.

The distinction between paper and paperboard is not sharp, but broadly speaking, the thicker, heavier, and more rigid grades of paper are called paperboard.

Paper Wrapped (PW) Lumber strapped into units and wrapped in weather resistant material prior to shipment.

Paragraph PART — Partition

Parenchyma Short cells having simple pits and functioning primarily in the metabolism and storage of plant food materials. They remain alive longer than the tracheids, fibers, and vessel elements, sometimes for many years. There are two kids of parenchyma cells; vertical strands, also known as axial parenchyma, and those in horizontal series, also know as ray parenchyma.
Parent Tree

Any tree whose seeds are used to product progeny for use in genetic experimentation. Usually the parent tree is selected because it displays characteristics either interesting from a research standpoint or desirable in an operational forest management program.


The aggregate component of particleboard manufactured by mechanical means from wood.


A type of manufactured plywood that is made from ground up and glued scrap wood. Particle board is very dense, heavy and flat.

Partial Cut

A logging area in which only part of the trees are felled and bucked, as opposed to clear cut.

Particleboard Core Plywood

Plywood that is made by gluing a thin layer of veneer to a piece of particleboard.

Partly Air Dried (PAD)

Seasoned to some extent by exposure to the atmosphere, but still considered green or unseasoned.



Pass Block

A light-weight block hung at the top of the spar tree and used to lift the bull block and other gear in rigging the tree.


Timber purchased based on a dollar amount for a certain amount/volume of wood, such as dollars per MBF. Payment is made only as timber is cut and transported.


The gross weight of a loaded vehicle minus the weight of the vehicle itself.

Payout To unreel cable.

Generally, unconsolidated material that consists mainly of un-decomposed, or only slightly decomposed, organic matter accumulated under conditions of excessive moisture. More specifically, a layer of organic material containing plant residues that may show little, if any, morphological change and that have accumulated as a result of submergence in water or through being in a very wet environment.


A stout wooden lever, fitted with a strong, sharp spike used for rolling logs.


Pockets or areas of disintegrated wood caused by advanced stages of localized decay in the living tree; it is usually associated with cypress and incense cedar; there is no further development of peck once the tree is felled.


To convert a log into veneer by rotary cutting.


A high-grade log from which veneer is peeled, on a lathe, for the production of plywood. Peelers are most frequently from old-growth trees. The resulting veneer is usually clear and used in sanded plywood.


Program for the Endorsement of Forest Certification Schemes, which was formally known as the Pan European Forest Certification Scheme.


A hardwood dowel usually ranging from 5/8 of an inch to 2 inches in diameter.

Pencil Stock Made from Incense Cedar, pencil stock is graded for the percentage of clear pencil squares that may be obtained from a piece by ripping and cross cutting.

An ornamental termination to the low end of a hammer post, king post, queen post, etc.


A system of measuring the size of a nail. Originally derived from a unit of weight, pennyweight is represented by the letter “d”.

Periodic Annual Increment (PAI)

Mean annual growth or increase in volume during a specific period of time.

  • Belongs in the Ebony family
  • Orange-brown streaks, in dark brown and black heartwood
  • Straight grain and fine and even texture
  • High bending and crushing strengths
  • Medium stiffness
  • Used for textile shuttles, cabinets, and paneling
Peruvian Walnut
  • Dark brown with blackish streaks
  • Straight to wavy grain
  • Medium bending strength and resistance to shock loads
  • High crush strength
  • Low stiffness
  • Works easily with hand and power tools
  • Nails and screws easily
  • Moderately durable
  • Used for high-class furniture, cabinet making, musical instruments, carving, sporting goods, and decorative veneer.

Precision End Trimmed

Phillips Head

A type of screw head requiring a driver in the shape of +.


The inner part of a trees bark that delivers water and other nutrients.


Photosensitivity is the degree in which all species change in response to natural sunlight or UV light. Contrary to popular belief, all species, both domestic and exotic are affected by sunlight. Depending upon how much natural sunlight or UV light the hardwoods receive will determine how quickly the change takes place. Red Oak, Maple, Hickory, and many other domestic species will generally fade in color and/or yellow as the urethane/stain is effected by the UV light. Generally exotic species will darken and richen in color with exposure to UV light. There are manufacturers who have UV inhibiting finishes on their products, and these will prolong the changes due to UV light, but this does not prevent them completely, the floors will still change.


The process that plants use to synthesize nutrients from water and minerals, using light.


A class of a group of plants. Phylum is a botanical term used by botanists to classify plants.


A sharpened or pointed pale, post, or stake usually used as fencing.

Piece Rate

Payment for labor where income is related to output.


A masonry post. Piers often serve as above-gate footings for posts and often are made of pre-cast concrete.


Located or formed at the base of a mountain range; an example would be piedmont terrace. Area, plain, slope, glacier, or other feature at the base of a mountain, such as a foothill or bajada. In the United States, the plateau extending from New Jersey to Alabama and lying east of the Appalachian Mountains is considered a piedmont.

Pike A long pole with a pointed steel head used in raising bents, also called a barn pole.

Round timber of any required size or length, usually used with smaller end in the ground.

Pilot Bit

A router bit fitted with bearing above the cutter which rides on the edge of a board or template, keeping the bit a fixed distance from the edge.

Pin Hole

From any cause approximately 1/16” in diameter.

Pin Knot

One knot over ½” in diameter.


Any evergreen tree of the genus Pinus, native to northern temperate regions. Trees with needle shaped sprees growing in clusters.

Pin Router

A router that is fixed above a table with its bit point down. A pin in the table is aligned with the bit and used to route the workplace.

Pintle Hook

Hooking device normally found on the rear of a piece of equipment and used to pull or attach a cable or trailer.


A colloquialism for a landing, also known as a deck or ramp.


The number of teeth on a saw blade per inch.

Pitch Pocket

A pocket of resinous sap confined within the grain of many conifers.

Pitch Seam

Shake or check which is filled with pitch.

Pitch Streak

A well-defined accumulation of pitch in the wood cells in a more or less regular streak.


A soft core in the center of a tree trunk.

Pith Fleck

A narrow streak, resembling pith on the surface of a piece, resulting from burrowing of larvae in the growing tissues of the tree.

Plain and Profile

A drawing showing both horizontal (plan) and vertical (profile) delineation of the road survey.


An instrument used to mechanically measure an area by tracing the perimeter on a place surface. This is typically used to estimate the size of an area from scale maps.

Plain-Sawn Lumber

A method of sawing lumber, where the log is cut tangential to the growth rings.

Planing Mill Products

Surfaced or planed lumber; products worked to pattern, such as flooring, ceiling, and siding.


A piece of lumber, from 2 but not including 5 inches thick, generally used with wide face horizontal.


A forest stand regenerated artificially either by sowing or planting.


An artificial regeneration method in which a new stand of trees is established by restocking the area with tree seedlings.


The major horizontal timber which runs from one end of the frame to the other and supports the base of the rafters.

Plate Joint

A butt joint that is reinforced with a football shaped “biscuit”. The biscuits are usually made from compressed pieces of wood, usually birch. When a biscuit comes into contact with glue in the joint, it swells creating a tighter joint.

Plasticizing Wood

Softening wood by hot water, steam, or chemical treatment to increase its moldability.


Pacific Lumber Inspection Bureau


A term used to describe something that is perfectly perpendicular to the earth relative to gravity. A plumb bob on the end of a string will give you a line that is plumb or straight up and down.

Plumb Bob

A usually conical metal weight attached to the end of a plumb line.

Plunge Cut

Starting a cut in the center of a log using the tip of the chain saw blade. This is also known as boring.

Plunge Router

A router mounted on a spring loaded base. The router can be turned on and plunged down into the work piece.


A flat panel made up of a number of thin sheets, or veneers, of wood in which the grain direction of each ply, or layer, is at right angels to the one adjacent to it. The veneer sheets are united, and under pressure, via a bonding agent.

Pneumatic Nailer

A nail gun activated by air pressure.


A well-defined opening between the rings of annual growth, usually containing pitch or bark.

Pocket Hole

A hole drilled on an angle with a step bit to make a butt joint. The larger hole is for the screw head to enter, and the smaller hole is for the shank.

Pocket Rot

Advanced decay which appears in the form of a hole, pocket or area of soft rot usually surrounded by apparently sound wood.

Pogo Stick

A stand used to hold the air hose and electrical connections mounted behind the cab on a truck tractor. This is also known as a hitchhiker.


Characteristics of a molecule in which the positive and negative electrical charges are permanently separated, as opposed to non-polar molecules in which the charges coincide.


Young tree at least 4 inches and less than 8 to 12 inches in D.B.H.

Pole Size

Trees from 5 to 11 inches in D.B.H.

Pole Timber

Arbitrary term for small sawn timber trees. Generally, trees 12 to 18 inches in D.B.H. This is also known as small saw timber.


A compound formed by the reaction of simple molecules having functional groups that permit their combination to proceed to high molecular weights under suitable conditions.


A chemical reaction in which the molecules of a monometer are linked together to form large molecules whose molecular weight is a multiple of that of the original substance.

Pond Value

Market price of logs delivered to a wet site, log pond, or tidewater.

  • Creamy-white to grey in color
  • Straight grained and fine texture
  • Very low stiffness and resistance to shock loads
  • Medium crushing strength
  • Low bending strength
  • Nails satisfactory and glues easy
  • Used for bottoms of trucks, wagons, and carts, drawers, interior joinery, toys, flooring, and boxes.
Porous Wood

Wood with larger than normal pores and vessels.


Something that can be picked up and carried from one location to another.

Portable Chipper Terms
  • Anvil – A fixed steel block that provides support and resistance for the chipper knife.
  • Chipper Deck – Infeed deck of a chipper, including the chain that feeds the material to be chipped.
  • Chipper Discharge – Denotes the direction chips leave the chipper housing. May be horizontal, overhead, or from the bottom.
  • Chipper Infeed – A series of rollers at the front portion of the chipper where the material to be chipped enters.
  • Chipper Knife- Replaceable piece of steel with sharpened edge; attaches to a rotating drum.
  • Chip Separator – Portion of a chipper that includes a chipper spout for the separation of needles and twigs from chips.
  • Chute – Out-feed portion of a chipper. This is also known as a discharge spout.
  • Counter Knives – A piece of steel that breaks a chip into desired lengths. Found behind, and similar in appearance to, the chipper, knife.
  • Fan – The part of a chipper that creates an air stream, moving the chips out of the chipper housing.
  • Feed Plate – A vertical plate of steel that prevents the tree in the chipper from passing beyond the disk.
  • Reed Rate – Distance the stock being chipped moves during a given interval of time or operational cycle.
  • Infeed Throat – The somewhat funnel-shaped portion of the Infeed that causes the tree to move forward to the feed and downward to the anvil.

Upright or vertical timbers erected within the frame that provide structural support of the members above.

Post Anchor

A metal piece attached to or imbedded in the footing that attaches the post to the footing and keeps the post from being exposed to moisture in the ground.

Post Cap

A small piece of wood attached to the top of the post to cover the posts wood grain and protect the post from the weather.

Post Cure

A treatment applied to an adhesive assembly following the initial cute, to complete cure, or to modify specific properties.

Posts and Timbers

Large pieces (nominal dimensions 5” by 5” and larger, width not more than 2” greater than thickness) of square or approximately square cross section graded primarily for use as posts or columns.

Potential Yield

The estimated maximum sustained yield cutting level (stated for a period of time such as a year or decade) attainable with intensive forestry; considers productivity of the land, conventional logging technology, standard cultural treatments, and interrelationships with other resource uses and the environmental. Excluded in the estimates are the effects of fertilization, genetic improvement, and irrigation, which have not yet been proven to be economically feasible over large portions of the country.

Power Shift

Transmissions that can be shifted while transmitting full engine power to the tracks or wheels.


Ponderosa Pine.

Precision End Trimmed (PET)

Lumber is trimmed square and smooth on both ends to uniform length.


Condition of too much cure, set, or solvent loss of the adhesive before pressure is applied resulting in inadequate flow, transfer, and bonding.


Any substance that, for a reasonable length of time, will prevent the action of wood-destroying fungi, bores or various kinds, and similar destructive life when the wood has been properly coated or impregnated with it.

Pressure Pricess

Any process of treating wood in a closed container whereby the preservative or fire retardant is forced into the wood under pressure greater than one atmosphere.

Pre-Commercial Thinning

Cutting trees from a young stand so that the remaining trees will have more room to grow to marketable size. Trees cut in a pre-commercial thinning have no commercial value and normally none of the felled trees are removed for utilization. The primary intent is the improve growth potential for the trees left after thinnings.


Moving pulpwood from a stump site to a truck loading site by carrying it off the ground. This is also known as forwarding.


To circle several logs with binders so the entire unit can be hauled as one log.


To remove small understory trees, windfalls, or special products such as poles or pilings from a stand ahead of the main logging to prevent breakage.


Cutting specified high-valued wood products such as poles and pilings before cutting the remainder of the trees.

Prescribed Burning

Deliberate use of fire under conditions where the area to be burned is predetermined and the intensity of the fire is controlled.


Any substance applied to wood that helps it resist decay, harmful insects, or rotting.


A process of impregnating lumber or other wood products with various chemicals, such as preservatives and fire-retardants, by forcing the chemicals into the structure of the wood using high pressure.

Preventive Maintenance

Maintenance measures taken in advance to avoid breakdowns.

Primary Logging Road

Road designed and maintained for a high level of use. Typically an all-weather gravel road that is used in a permanent road system.

Primary Transportation

Movement of a felled tree from the stump to a landing.

Primary Wood

This is the wood that is on the main or primary surfaces of a piece of furniture. These are the premium or money woods of the cabinet.

Prime Log

A log that is a given size and free from defects.

Principle Rafters

A pair of inclined timbers that are framed into a bend and used with either purlins or secondary rafters or alone.

Priority Sequence

The order in which items are to be yarded.


An independent operator who produces and delivers pulpwood to a deal or pulpwood company.

Productive Machine Hour (PMH)

Time during scheduled operating hours when a machine performs it’s designated function (time exclusive of such things as machine transport, operational or mechanical delays, and servicing or repair).

Program for the Endorsement of Forest Certification (PEFC) Schemes

An organization that was developed to address the issues of the multitude of certification programs with competing standards and serves as an endorsement system that provides international recognition for national forest certification programs.


To protrude above the surface so it is sticking out a bit.


Removal of live or dead branches from standing trees, usually the lower branches of young trees and of multiple leaders or shoots in plantation trees – for the improvement of the tree or its timber. Cutting away of superfluous growth, including roots, from any plant to improve its development.


An instrument for measuring the amount of water vapor in the atmosphere.


Pressure Treated


Mechanically ground or chemically digested wood used in manufacturing paper and allied products.

Pulp Hook

A curved steel hook with a wooden cross handle; used in handling pulpwood.

Pulp Log

A log that does not meet the one-third merchantability standard for a sawn log but contains a minimum of 50-percent sound wood fiber by volume.

Pulp Mill

A mill that converts pulpwood to wood pulp.

Pulp Trees

Small trees and saplings that will be ground to produce paper. Lumber farmers often over-plant their acreage and remove smaller trees for pulp as the crop matures.


Round wood used as a source of wood fiber in a pulp mill. Wood cut or prepared primarily for wood pulp and subsequent manufacture into paper, fiberboard, or other products, depends largely on the species cut and the pulping process.

Pulpwood Dealer

The middleman who buys pulpwood from the producer and sells it to the pulp mill company or acts as a commission broker for the company in producing pulpwood.


A fine, abrasive powder that is made from volcanic ash. Pumice is used with a felt block in woodworking to rub out (polish) a finish.


A horizontal member of the roof frame which runs between rafters.

  • Deep-purple violet when freshly cut
  • Straight grained, sometimes interlocked
  • Moderate to fine texture
  • High strength in bending, stiffness, and crushing
  • Medium resistance to shock loads
  • Rather difficult to work with
  • Very durable
  • Used for heavy outdoor construction, bridge building, dock work, flooring, tool handles, furniture, and billiard tables.
Push Stick

A tool used that is to safely push a board through a table saw or other power tool.


Paper Wrapped

Lumber Glossary Term Definition

One Quadrillion (1 X 10(15))

Quality Classes
  • Mortality of Growing Stock – Volume of sound wood in live sawn timber and pole timber trees dying annually from natural causes. Natural causes include fire, insect disease, and animal damage; weather and suppression.
  • Mortality of Saw Timer – The net board-foot volume of sawn timber trees dying annually from natural causes.
  • Net Annual Growth of Growing Stock – Annual change in volume of sound wood in live sawn timber and pole timber trees, plus total volume sound wood in live sawn timber and pole timber trees, plus total volume of trees entering these classes through growth, minus volume losses resulting from natural causes.
  • Net Annual Growth of Saw Timber – Annual change in volume of live sawn timber trees plus total volume of trees reaching saw timber size, minus volume losses resulting from natural causes.

A method of cutting lumber where the annual rings are relatively perpendicular to the face of the board. Quarter-sawn lumber tends to be more dimensionally stable then other forms of lumber, such as plane-sawn.

Quarter-Sheet Sander

A vibrating sander that uses ¼ size piece of sand paper. It is not an aggressive sander and removes very little material. Optimal for finishing flat surfaces.

Queen Posts A pair of vertical posts of a roof truss standing on the bent or girt and supporting the rafters or collar tie.
Lumber Glossary Term Definition
R/L (RL)

Random Lengths

R/S Resawn
R/W (RW)

Random Widths


R/L (RL)

Rack and Pinion A system using two gears, one round, and one flat, to move a part. An example would be a drill press; a round gear connected to a handle works with a flat gear on the column to raise and lower the table.

Coincident with a radius from the axis of the tree or log to the circumference; in a round timber or piece of lumber, a line or surface extending outward from the heart-center; a radial surface is always edge-grain.

Radial Arm Saw A circular saw that runs on an overhead track; the track mechanism swings in relation to the table to make miter cuts.
Radial Drill Press

A drill press with the head mounted on a tube which is laterally and vertically adjustable. This type gives greater throat clearance but is not as solid as a conventional drill press so run out can be a problem.

Radial Shrinkage Shrinkage in a piece of lumber that occurs across the growth rings as it begins to dry.

The sloping main line of the roof frame.

Rail A horizontal board that runs along the underside of a table; the horizontal part of a raised panel door.
Rail Post

A vertical structural support for the railing, sometimes also supporting the deck itself and extending down to a footing. Rail posts are thicker than balusters and are attached with bolts to the joists or beams.

Railroad Tie A piece of industrial lumber used to support rails on a roadbed. In Britain and other countries it’s known as a “sleeper”.
Raised Grain

The roughened condition of sanded wood when the hard latewood rises above the soft earlywood when moisture is applied.

Raised Panel

A piece of wood that is the center of a frame and panel assembly.


The angle at which the leading edge of the teeth are cut on a saw blade.


A tooth set that has a uniform set angle and a three tooth set sequence of left, right, and straight.

Ram Set Gum

A nail gun used in construction and manufacturing to join materials to hard substances such as steel and concrete.

Random Lengths

Lumber of various lengths, usually in even two-foot increments. Lumber offered as random-lengths will contain a variety of lengths which can vary greatly between manufacturers and species. A random-length loading is presumed to contain a fir representation of the lengths being produced by a specific manufacturer.


A long and flat steel tool with raised teeth for shaping wood; some rounded on one side.

Rate of Growth

The speed at which a tree increases in size. This may be measured radically in the trunk, or in the dimension of the crown or other tree part. One unit of measure in wood is in number of annual growth rings per inch.


A generic term used to describe certain tool movements, such as the cone-to-slip engagement on permanent packers or plugs.


A ribbon like figure caused by the strands of cells which extend across the grain in quarter-sawn lumber.

RC Red Cedar



A wooden or metal structural member connecting a logging trailer to a truck tractor.

Reaction Wood

Abnormal wood tissue that was formerly in a leaning tree. Reaction wood is very unstable and extremely prone to warping and cupping when sawn into lumber. This wood has distinctive anatomical and physical characteristics. This characteristic is typical in parts of leaning or crooked stems and in branches; it tends to restore to the original position of the branch or stem if this has been disturbed. This is also known as tension wood.

Reciprocating Saw

A portable power saw with a reciprocating blade. Can be used with a variety of blades depending on the application and kind of cut; generally has a plate that rides on the surface that is being cut.


An exceptionally large Californian conifer, Sequoias semervirens, which yields red wood. This is a hot favorite as a decking timber because of the natural decay resistant qualities and beautiful tones.

Red Oak
  • Pinkish with a red tinge
  • Mostly straight grained
  • Coarse textured
  • Medium bending strength
  • High crushing strength
  • Used for flooring, furniture, and interior joinery.

Restocking an area with forest trees.

REG Regular

Renewal of a tree crop, either by natural or artificial means.


A statistical technique used to evaluate relationships among variables.



Relative Humidity The amount of moisture in the air that is measured as a percentage of the total amount of moisture the air can hold at a particular temperature. This is known as relative humidity. The ideal relative humidity for a home is between 35% and 45%. Too much above or below these levels can lead to problems occurring.
Reload To transfer logs from one mode of transportation to another or between vehicles.

To salvage small timber, culls, and other residuals following the main logging operation.

Remote Deck

A freestanding platform located away from the house, typically placed for a good view.


Trees remaining after an intermediate or partial cutting of tree crops or stands. In general, residuals are by products of an operation. Examples are chips from lumber production and hog fuel from any wood processing operation. This is also known as waste.

Residual Stand

Trees remaining in an area after the cutting operation has been completed.

Residual Value

The actual or assumed value of a machine after it has been fully depreciated.


Wood or bark that is left after a manufacturing process.


The property where a strained body gives up its stored energy on the removal of the deforming force.


An organic material that has an indefinite and often high molecular weight, exhibits a tendency to flow when subjected to stress.

Resin Ducts

Intercellular passages that contain and transmit resinous materials.

Retention by Assay The determination of a preservative retention in a specific zone of treated wood by extraction or analysis of specified samples.

The study of the deformation and flow of matter.


A pile of evenly stacked cordwood, stave, bolts, or other short-length wood.

Ridge Beam

A horizontal timber to which the tops of rafters are fastened. This is also called a ridge board or a roof tree.

Ridge Pole

A horizontal timber which connects rafter pairs at the peak.

Ridge Purlin

The beams connecting rafter to rafter at the apex.

Rift Lumber

Diagonally grained lumber.


To install the blocks and lines used in a cable logging system.


Cables, blocks, and other equipment used in yarding logs.


A strip of land on which a road is to be constructed.


A circular rot in a log. Any rot localized mainly in the springwood of the growth rings, giving a concentric pattern of decayed wood in the cross section of a tree or log.

Rink-Shank Nail

A nail with grooves and ridges around the shank to prevent the nail from popping out of the wood as the wood contracts and expands because of changes in moisture and temperature.

Riparian Right

A right of someone owning land located on the bank of a natural watercourse, such as a river, lake, or tidewater, to access or use the shore, bed, or water.

Rip-Cut (Ripping)

A cut made parallel to the grain of a board.

Ripple Marks

Fine horizontal striations visible on the tangential longitudinal surfaces of certain wood. Due to the stories arrangement of the rays or of the axial elements or of both.


Rough stones of various sizes placed compactly or irregularly on the ground surface to prevent scouring by water or debris.


Redwood Inspection Service


The vertical distance from one stair tread to another.


The vertical piece between two stair steps.

Robertson Head

A screw head requiring a driver with a square tip. This is also referred to as a socket head.


A roller that has an absorbent surface used for spreading paint.

Roof Truss

An engineered building component that supports the roof in place of rafters. Roof trusses are constructed in a triangular shape with a number of interconnected pieces that spread a load evenly across the truss.


Roll-over protective structures that protect the operator if a machine overturns.


A machine that peels bark using knives.

Rotary Planar

A power hand tool with rotating blades that smoothes the surface of material.

Rotary-Cut Veneer

Veneer which was cut from a log in one long sheet. Rotary cut veneer is cut from a log like a roll of paper towels.


Period of years between establishment of a stand of timber and the time when it is considered ready for final harvest and regeneration. The planned number of years between the regeneration of a timber stand and its final cutting.

Rough Cut

Lumber that has not been dressed (surfaced) but which has been sawn, edged, and trimmed to at least show saw marks in the wood on the four longitudinal surfaces on each piece for its overall length.

Rough Lumber

Lumber which has not been dressed or surfaced but has been sawn, edged, and trimmed.

Rough-Edge Lumber

Boards having attached bark on both edges.


Lumber that is either green or dried that has not been dressed (planed).

Round Wood

A length of cut tree generally having a round cross-section, such as a log or bolt.

Round Wood Products

Logs, bolts, or other round sections cut from trees for industrial or consumer use.


A high speed motor with handles and an adjustable base with a collet that accepts profile bits to cut dados, rabbets, and shapes.

Rub Bearing

A ball bearing rub collar near the top or bottom of a spindle shaper that is used to keep the work piece a fixed distance away from the cutters.

Rub Tree

A tree used as a fender or pivot to protect the remaining stand during yarding.

Rule Joint

A joinery method used in drop left tables where the tabletop has a convex profile and the left has a concave cut. The two pieces are joined by a hinge.


The horizontal distance from one stair riser to another, the depth of a stair step.


The amount of wobble in a shaper or router.

Running Line

A moving cable

Running Skyline

A system of two or more suspended moving lines, generally referred to as main lines and haul-back lines. Will provide lift and travel to the load carrier when tension is properly applied.


Random widths and random lengths.



Lumber Glossary Term Definition

Surfaced one face

S2S Surfaced two faces

Surfaced two sides, one edge


Surfaced two faces and straight line ripped one edge

S4S Surfaced two faces and straight line ripped two edges

Society of Automotive Engineers

Safety Guy A line rigged under the bull block to take it to the ground if the holding straps break.
Safety Swede

A lever used to tighten binders on loaded logging trucks.

Sag Slack in a cable, particularly in a skyline.
Salvage Logging

A cleanup operation, generally with a small crew and light equipment, which collects merchantable material too small to be handled economically with big equipment. Salvaging timber damaged by wind, insect, fire, ice, or other natural causes.

Sand Bolster Part of a landing gear that rests on the ground, across and between the two upright portions.
Santos Mahogany
  • Range of colors between light orange to a dark reddish-purple brown
  • Interlocked grain
  • Moderately difficult to machine
  • High density
  • Used for fine furniture, interior millwork, hardwood flooring, stairs and molding.
Sap The water in a tree which is rich in minerals and nutrients.

Young tree less than 4 inches in D.B.H. The minimum diameter or saplings is usually, although not always, placed at 2 inches.


The new wood in a tree that lies between the bark and the heartwood. Sapwood is usually lighter in color and becomes heartwood as the tree ages.


A frame structure, normally glazed, that is hung or fixed in a frame set in an opening.


A trestle usually used in pairs to hold wood for cutting.


A basic, cutting process that uses a blade set with a series of teeth on its edge to cut a narrow opening in a work piece. Sawing may be used to produce slots or grooves or to separate the work piece into two pieces.

Saw Kerf

Grooves or notches that are made in cutting with a saw.

Sawlog Portion

That part of the bole of saw timber trees between the stump and the saw log top.


Logs meeting minimum regional standards of diameter, length, and defect. Logs must be at least eight feet long, have a minimum diameter inside bark of six inches for softwoods and eight inches for hardwoods, and maximum defect as specified by regional standards.

Saw Timber

Trees suitable for production of saw logs.


A brand of reciprocating saw manufactured by the Milwaukee Electric Tool Company.

Scale ‘lb’ measure the weight or volume of a log or load of logs.

Determination of the gross and net volume of logs using the customary commercial volumetric units for the product involved.


Removing small plants and duff or ashes from around the spot where a tree seedling will be planted. This is usually done by hand rather than by machine.


A temporary platform either supported from below or suspended from above, on which workers sit or stand while performing tasks at heights above the ground.


Shallow loosening of the soil surface.

Scarf Joint

A joint used to splice two timbers end to end.

Schedule Maching Hour Time in which a machine is intended to be operated and has an operator scheduled.
Schoolmarm A tree that initially had a single trunk that later split into two separate trunks part way up the tree.

A two-runner sled, without tongue or shafts, used to haul logs or bolts from the woods.

Screw Gun

A tool used to install sheetrock, also known as drywall. Screw guns look like a normal drill, although they have a “nose” as opposed to a chuck. The nose holds an interchangeable shank bit, commonly known as a tip.


Shaping one member to the surface which it touches; for example, to fit a board snugly to a surface which is not straight.

Scribner Rule The diagram log rule, one of the oldest in existence, that assumes 1-inch boards and ¼-inch kerf, make a liberal allowance for slabs, and disregards taper. This is the official rule of the Canadian Forestry Branch, Department of Resources and Development, and also used in many part of the United States.
Sealed Bid Sale Sale in which interested parties submit written bids at the time and place specified.

Wood that has been dried to a certain moisture content to improve its serviceability. According to the grading standards of the Western Wood Products Association, seasoned softwood lumber is defined as having a moisture content of 19% (oven-dry basis) or less.


The process of removing the moisture from green wood to improve its workability and stability.

  • Air Dried – Dried by exposure to air in a yard or shed, without artificial heat.
  • Kiln Dried – Dried in a kiln with the use of artificial heat
Second Growth

Trees that come up naturally after the first growth of timber has been cut or destroyed by fire. This is also known as young timber.

Secondary Logging Road

A road designed for relatively little use. Typically, a dirt road, with no gravel, used only during dry weather.

Secondary Rafters

Smaller sized timber rafters placed between principle rafters.

Secondary Transport

Movement of wood from the landing or transfer point. This includes movement by truck, rail, or water.

Secondary Wood

This is the material used in furniture that is not seen or on the sides or back of an object. These are the materials that make up the drawer sides, dust panels, backs and other hidden parts.


A land survey subdivision. This is usually one square mile (640 acres).


An area prepared to receive seeds, such as an area cleared of plants and duff, so that natural seed fall can establish a new forest.

Seedling A young tree grown from a seed, from the time of germination until it reaches sapling size. In nursery practices it is a young tree that has not been transplanted.
Seedling and Sapling Stands

Where ten percent of the stand consists of growing-stock trees, and saplings and/or seedlings constitute more then half this stocking.

Seed Block

Used to describe uncut blocks of trees that are left between and around small clear-cut blocks to provide seeds for natural regeneration.

Seed Tree

A horizontal timber to which the tops of rafters are fastened. This is also called a ridge board or a roof tree.


In softwood lumber, the highest appearance grades are Select grades, usually separated as “B and better”, “C”, and “D” select grades. In hardwood factory lumber, Selects is one specific grade, placing in quality below Firsts and Seconds, but higher than Common grades.

Select Grade

High-quality lumber. This grade is recommended for all finishing uses where fine appearance is essential. Widely used for high-quality interior trim and cabinet work with natural, stain, or enamel finishes.

Selection Cutting

Cutting only a portion of the trees in a stand; usually those marked or designated by a forester.

Selection System

Uneven-aged silvicultural system in which single or small groups of trees are periodically selected to be removed from a large area so that the age and size classes of the reproduction are mixed.

Selection Thinning

Removal of dominant trees that have exceeded the diameter limit prescribed; in favor of smaller trees with good growth form and condition. This will promote conversion to a selection forest.

Selective Cut

A type of timber harvesting that removes only certain species above a certain size or value.


In softwood, lumber which has been graded strictly for its appearance. In hardwood, lumber which is one grade below first and second.

Self Loader

Logging truck with a loading device, generally a knuckleboom loader, mounted behind the cab.

Semitransparent Stain

A suspension of pigments in a drying oil designed to color and protects wood surfaces by penetration without forming a surface film and without hiding wood grain.

Separator Wood

Material that has been separated from the whole tree during the chipping process and is unacceptable for pulp and paper manufacture. This is usually used as energy wood.


The teeth are offset on each side of the blade to allow clearance for the thickness of the blade.


Area logged to an one yarder set-up.


The area along a property’s edge where new construction is restricted or forbidden by local zoning laws.


A clevis or U-shaped metal fitting with a pin through the ends.

Shade Structure

A structure built above decks, usually of posts and lattice, to provide a shaded area on the deck.


A lumber defect that is a lengthwise separation of wood; along the growth rings.


Shakes are very similar to checks, but usually wider and longer. They generally work from the heart of the tree outward, at right angles rather than parallel to the growth rings.


A machine with an interchangeable rotary cutter head to cut profile shapes on the edge or face or material


A small wood particle of indefinite dimensions developed incidental to certain woodworking operations involving rotary cutter heads usually turning in the direction of the grain.

Shay Swivel

A fitting used to attach the slack-pulling line to the main line on a skyline system.


Hydraulically operated scissor-like device for crosscutting the stem of a tree. One type of tree shear uses a cutting blade, which closes parallel to the anvil.

Shearing Strength

The capacity of an object or soil to resist shearing stresses.


Lumber, Plywood, oriented strand board, or wafterboard used to close up side walls, floors or roofs prior to the installation of finished materials on the surface. The sheathing grades are also commonly used for crates, pallets, and certain industrial products.


A grooved wheel or pulley.

Sheep’s Foot Roller

A steel drum with short metal rods on the outside; sometimes shaped like a sheep’s foot. This is used for compacting soil.


Resin flakes dissolved in alcohol used as a finish for wood.

Shelterwood Logging

A method of harvesting timber so that selected trees remain scattered throughout the tract to provide seeds for regeneration and shelter for seedlings.

Shelterwood System

Even-aged silvicultural system in which a new stand is established under the protection of a partial canopy of trees. The mature stand is generally removed in a series of two or more cuts, the last of which is when the new even-aged stand is well developed.

Shipping Dry

Having moisture content (over-dry basis) of 14 to 20 percent. Results in reduced shipping weight and less susceptibility to decay. This is used in the international lumber trade.

Short Rotation Energy Plantations

Plantings established and managed under short-rotation intensive culture practices.

Short Ton

U.S. weight measure equal to 2,000 pounds.


Pulpwood less than 120 inches in length. Trees or stemwood portions of trees delivered in product lengths of less than 15 feet and normally considered only for pulpwood.


A two-drum, live skyline yarding system used in uphill logging, in which the carriage moves down the skyline by gravity, is lowered to attach logs, and is then raised and pulled to the landing by the main line.


The area of the void created when the waste around a tenon has been cut away.


A tool with a handle and a broad scoop or blade for digging and moving material, such as dirt or snow.


Any unit of operation in the woods associated with timber harvesting.


A decrease in wood dimensions due to loss of water in the wood cell walls. Shrinkage across the grain of wood occurs when the moisture content falls below 30 percent, the fiber saturation point. Below the fiber saturation point, shrinkage is proportional to moisture content, down to a moisture content of zero percent. Shrinkage is expressed as a percentage of the green wood dimensions.

Shuttle Hauling

Use of preloading trailers to reduce truck turn-around time.


A term for an adjoining object being below the object it is next to. This means a little below the surface.


Men and equipment needed to yard and load any one logging unit of an operation.


The finish covering of the outside wall of a fame building, whether made of horizontal weather boards, vertical boards with battens, shingles, or other material.

Sill Timber

Major horizontal timbers which lie on the foundation and form the lowest part of the frame.

Silvicultural System

The process of tending, harvesting, and replacing forest trees, which results in the production of forests with distinct compositions. Systems are classified according to the method of harvest cutting used for stand reproduction.


The science and art of cultivation (such as with growing and tending) forest crops, based on the knowledge of silvics. More explicitly, the theory and practice on controlling the establishment, composition, constitution, and growth of forests.

Single-Action Shear

A mechanized cutting tool that uses one hydraulic cylinder to push the cutting blade through the tree while a fixed anvil provides support for the blade on the trees opposite side.

Single-Span Skyline

Skyline without intermediate support spars.


An operation handling one tree at a time.

Site Class

Classification based on ecological factors and the potential production capacity of an area; a measure of the relative production capacity of a site.

Site Built

A structure constructed at the site where it is to remain.

Site Index

The measure of forest productivity generally expressed as the height in feet of dominant and co-dominant tree species at a specific index age such as 25, 50, or 100 years. Sit indexes are normally grouped by site classes.

Site Preparation

Removal or deadening of unwanted vegetation prior to planting trees; includes prescribed burning, use of herbicides, disking and other mechanical means of removing vegetative cover.

Site Utilization

A term used when indicating the proportion of a useable forest site occupied by healthy, vigorous forest crop trees at any one point in time.


A motor truck with six powered wheels, two in front and four in back.


A load being pulled by the skidder.

Skidding Chain

The length of chain fastened around the end of a log.

Skidding Pan

A plate of heavy steel, round in front, placed under the front end of logs being skidded to prevent them from digging into the ground.

Skidding Tong

The tong used in skidding to grasp a log.

Skid Pole

Logs or poles, commonly used in pairs, on which logs are rolled.

Skid Trail

Skidder path through the woods.


A decorative board placed around the support structure of a deck to hide the structure below and give the deck a finished appearance. Skirts often are attached to the joists.


Cableway stretched tautly between two spar trees and used as a track for a skyline carriage.

Skyline Carriage

A wheeled device that rides back and forth on the skyline for yarding or loading.

Skyline Crane

A yarding system capable of moving logs laterally to a skyline as well as transporting logs either up or down a skyline to a landing.

Skyline Crane Carriage

Skyline carriage that incorporates provisions for pulling slack in the skidding line.

Skyline Road

An area bounded by the length and lateral yarding width of any given skyline setting.

Skyline Slope

The slant or inclination of the skyline chord, generally expressed as a percent.

Slackline System

A live skyline system employing a carriage, main line, and haul-back line. Both main and haul-back lines attach directly to the carriage. The skyline is lowered by a slackening of the line to permit the chokers to be attached to the carriage. Lateral movement is provided by side blocking. For drum standing skyline yarding systems in which either the slack pulling line pulls the main line through the carriage or a carriage that contains a skidding line is used. The haul-back line returns the carriage and holds it in place during lateral yarding.

Slack-Pulling Line

A line used to pull the main line through a logging carriage.


Woody material or debris left on the ground after an area is logged. This is also known as brush.


A machine that bucks Longwood into Shortwood at the landing. This is always known as a bucker.


A wide bladed and long handled chisel pushed by hand to create flat surfaces.

Sliding Miter Saw

A compound miter saw with horizontal sliding arms for the cutter head, allowing much wider cuts.


A loop of wire rope used in loading logs too large to be handled by tongs.


Relative movement in the direction of travel at the mutual contact surface of the traction or transport device and the surface that supports it.

Slip Grab

A pear-shaped link, attached by a swivel to a chain. The chain runs freely through this chain when the large end is down but catches and holds when the small end is down.

Slip Hook

A rounded hook that permits a chain to run freely through it.


A two-runner sled to haul logs or bolts out of the woods. Similar to a scoot except that the sloop is equipped with a tongue.

Small Trees

Live trees 1.0 to 5.0 inches to D.B.H.


A general term describing small-diameter material (such as what might be removed by a pre-commercial thinning) that is typically unsuitable for commercial roundwood products.


A standing dead tree from which the leaves and most of the branches have fallen.


The tendency to gouge the trailing end of material when running it through a joiner.

Snubbing Line

A line used for lowering a load.

Soil Reaction Nomenclature
  • Soil Adhesion – The sticking of soil to foreign materials such as soil implements, tracks, or wheels.
  • Soil Compaction – Increased soil density resulting from the packing effect of machines moving over the soil. Compaction disturbs the soil structure and can cause decreased tree growth, increased water runoff, and soil erosion.
  • Soil Failure – Alteration or destruction of the soil structure by mechanical forces such as in shearing, compression, or tearing.
Soft Rot

Rot occurring in the outer wood layers under very wet conditions.


Lumber often from a conifer, such as pine or cedar. The name softwood does not refer to the density of the wood. There are some hardwoods which are softer then some softwood.

Soft Maple
  • Creamy white and straight grained
  • Medium bending and crushing strengths
  • Low stiffness and resistance to shock loads
  • Works satisfactorily with hand and machine tools
  • Used for domestic flooring, interior joinery, piano actions, sports goods, and paneling
Solid Piling (Bulk Piling)

The close stacking of lumber or other products, without separation of layers with stickers, as in open piling.


The separation of forest products. This usually occurs at the landing.


A term referring to a board which has no or very few defects which will effect its strength.

Sound Wood

Wood that is free from defect.

South American Lacewood
  • Pink to reddish-brown color
  • Highly figured
  • Straight grain with a fine to medium texture
  • Medium strength
  • Low stiffness
  • Works well with hand and machine tools
  • Used for furniture, cabinet making, light construction, paneling, ornamental inlay, and decorative uses.
South American Mahogany
  • Heartwood ranges from light to dark reddish-brown
  • Straight to interlocked grain
  • Medium to coarse texture
  • Low bending strength
  • Medium crush strength
  • Very low stiffness and resistance to shock
  • Used for high-class furniture and cabinet making, reproduction furniture, boat interiors, carving, turnery, and molding
Southeastern States

Virginia, North Carolina, South Carolina, Georgia, and Florida.

Southern States

Alabama, Mississippi, Texas, Louisiana, Arkansas, and Tennessee.

Southern Yellow Pine

A species group composed of primarily of Loblolly, Longleaf, Shortleaf, and Slash Pines. Various subspecies are also included in this group. This group refers to the Southeastern United States, from Texas to Virginia.

Spacing Control

The act of creating, within the limits of the existing stand, a uniform distribution of trees that provides optimum growing space for each tree by eliminating overcrowding. As a result, tree diameter growth is increased and the time required for the forest to reach harvestable size is decreased.

Spade Bit

These are an inexpensive bit, suitable for general use, they get their name from their shape.


The width of a building or overall length of a truss.

Spanish Cedar
  • Pale pinkish-brown heartwood
  • Straight grain, sometimes interlocked
  • Moderately coarse texture
  • Strong in relation to its weight
  • Easy to work with hand and power tools
  • Durable
  • Premier wood used for cigar humidor interiors, furniture, cabinets, paneling, flooring, boat building, clothing chests, decorative veneers, and plywood.
Spar Tree

A tree or mast on which rigging is hung for one of the many cable hauling systems.


A category of biological classification; a class of individuals having common attributes and designated by a common name. “Species” is always properly used with the “s” when referring to trees or other biological classifications.

Specific Adhesion

Adhesion between surfaces that are held together by valence forces of the same type as those that give rise to cohesion.

Specific Gravity

The ratio of the weight of wood to an equal volume of water. The higher the specific gravity, the heavier the wood.


A defect that’s caused by a fungus living in a tree, which appears as small white pits of spots.

Speed Square

The rafter angle square is a triangular-shaped measuring tool used to draw straight lines on lumber to be cut, or to lay out angles for roofs, stairways, decks and other general construction. The tool is marked with degree gradations for fast layout and cutting of lumber without performing complex trigonometry calculations.


A narrow, turned piece of wood.


An attractive dark brown or black stain in some woods caused by decay. A change in the texture, strength and color of wood caused by colonies of fungus growing within the dead wood.


One who joins two pieces of cable together by intertwining the wire strands.


A separation of wood fibers that extends completely through a piece of lumber, usually at the ends.


A thin strip of wood fitting between two grooves to make a joint.


Used to shape curved surfaces, consists of a blade fastened between two handles, blades come in straight concave and convex curves.


To place a truck or trailer in position for loading.

Spray Gun

A cloud of mist of fine liquid particles, as of water from breaking waves.


The quantity of adhesive per unit joint area applied to an adherent.

  • Single Spread – Refers to application of adhesive to only one adherent of a joint.
  • Double Spread – Refers to application of adhesive to both adherents of a joint.
Spring Steel Alloy

A type of hardened steel that has both hardness and yield strength.


Tool with a narrow-shaped, curved blade used in removing bark by hand. This is also called a barking iron.

Spur Road

A road that supports a low level of traffic, such as a level that would serve one or two settings. Little or no engineering design work is needed to build it.

Spruce-Pine-Fir (SPF)

Canadian woods of similar characteristics that have been grouped for production and marketing. The SPF species have moderate strength, are worked easily to take paint readily and hold nails well. They are white to pale yellow in color. The largest volume comes from eastern Canada, where the principal species in the group are: Black Spruce, Red Spruce, Jack Pine, and Balsam Fir. The principal species of the group originating in Western Canada are Alpine Fir, Engelmann Spruce, Lodgepole Pine, and White Spruce. Some lumber production in the New England State also is marketed as Spruce-Pine-Fir (south).


An instrument used to lay out or test right angles, with two arms at 90 degrees to each other; the longer and wider arm is the blade, the shorter narrower arm is the tongue.

Squeeze Out

Bead of adhesive squeezed out of a joint when pressure is applied.

Stacked Dado Head

style of dado cutter has two outside saw blades, using a combination of chipper blades and shims between them the width of the dado is set.


A mobile machine for unloading and stacking or decking logs using the forklift principle and curved top clamps. A heavy-left machine similar to a front-end loader, with forks and clamps capable of handling and loading logs.

Staggered Setting

Cleat-cut settings separated by uncut timber.


A discoloration in wood caused by a chemicals, fungus, or minerals. A dye or pigment used to discolor wood.

  • Blue Stain – A bluish discoloration of the sapwood caused by the growth of certain dark-colored fungi on the surface and in the interior of the wood.
  • Brown Stain – A rich brown to deep chocolate-brown discoloration of the sapwood of some pines caused by a fungus that acts much like the blue-stain fungi.
  • Chemical Brown Stain – A chemical discoloration of wood, which sometimes occurs during the air drying or kiln drying of several species, apparently caused by the concentration and modifications of extractives.
  • Sap Stain – A discoloration of the sapwood caused by the growth of certain fungi on the surface and in the interior of the wood; made possible by the same conditions that favor the growth of other fungi.
  • Sticker Stain – A brown or blue stain that develops in seasoning lumber where is has been in contact with the stickers.

In Silviculture and management, a tree community that possessed sufficient uniformity in composition, constitution, age, spatial arrangement, or condition to be distinguishable from adjacent communities. This tree community forms a silvicultural or management entity; for example, a sub-compartment. Both natural and artificial crops are included, and there is no connotation of a particular age. In Mensuration, the amount of timber and/or fuelwood standing on an area, generally expressed as volume per unit area; for example, board feet per acre or cubic meters per hectare. In the United States, growth of trees on minimum of one acre of forest land that is at least 16.7 percent stocked by forest trees of any size.

Stand Condition

The general health of a stand of trees reflected by its development relative to the site potential. A good stand condition refers to a fully stocked stand that is producing fiber at a high rate based on specific site conditions such as moisture, soil quality, and other biological variables.

Stand Density

The number of merchantable trees per acre. A quantitative measure of tree stocking frequently expressed in terms of number of trees, basal area, or volume per unit area.

Stand Improvement

Measures such as thinning, release cutting, girdling, weeding, or poisoning of unwanted trees to improve growing conditions.

Stand Size Classes
  • Non-stocked Areas – Commercial forest land on which the stocking of growing-stock trees is less than 16.7 percent.
  • Poletimber Stands – Stands at least 16.7 percent stocked with growing-stock trees, with half or more of this stocking in sawtimber and/or poletimber trees. Stocking of trees exceeds that of sawtimber stands.
  • Sapling-Seedling Stands – Stands at least 16.7 percent stocked with growing-stock trees, with saplings and/or seedlings comprising more than half of this stocking.
  • Sawtimber Stands – Stands at least 16.7 percent stocked with growing-stock trees, with half or more of this stocking in sawtimber or poletimber trees. Sawtimber stocking at least equals poletimber stocking.
Stand Table

A table showing the number of trees by species and diameter classes, generally per unit area of a stand. Such data may be presented in the form of a frequency distribution of diameter classes.


A tooth form that has evenly spaced teeth, deep gullets, and a zero-degree rake angle.

Standing Line

A fixed cable that does not move during logging operations; for example, a skyline anchored at both ends.

Static Bending



The main body of a tree from which branches grow. Used loosely to refer to trees. For example, stems per unit area.


Wood from the main part of a tree, not from the branches, stump, or root.


A piece of short pulpwood.


A ¾” to 1” wood strip that is inserted between stacks of green wood and spaced between 16” to 24” to allow air to flow through the stack to ensure proper drying.

Sticker Stain

Sometimes called shadow, it’s a stain that forms under the stickers in a stack of drying wood.

Stiff Leg

A loader with a boom that does not swing.


The decorative end of a chamfer.

Story Stick

A “story stick” or “story pole” is a scrap strip of wood used to record dimensions for a project on site, then the dimensions are used in the ship to build the project. This method reduces the chance or error due to misreading numbers etc.


A term applied to the axial cells and rays in wood when these are arranged in horizontal series on tangential surfaces.


A short cable with a loop at each end.


A stripe of ribbon pattern that occurs when woods with interlocked grain, which slopes in alternate directions, are quarter-sawn.


A handle of a peavey or cant hook.


The degree of utilization of land by trees. Measured in terms of basal area and/or the number of trees in a stand compared to the basal area and/or number of trees required to fully utilize the growth potential of the land. A stocking percent of 100 indicates full utilization of the site and is equivalent to 80 square feet of basal area per acre in trees five inches in D.B.H. or larger. A stocking percent of 100 in a stand of trees less than five inches in D.B.H would indicate that the percent number of trees is sufficient to produce 80 square feet of basal area per acre when the trees reach five inches D.B.H. A stocking percent over 100 is fully utilizing the site.

Stocking Classes
  • Fully Stocked Stands – Stands in which the stocking of trees is from 100 to 133 percent.
  • Medium Stocked Stands – Stands in which the stocking of trees is from 60 to 100 percent.
  • Non-Stocked Areas – Commercial forest land on which the stocking of trees is less than 16.7 percent.
  • Over-Stocked Stands – Stands in which the stocking of trees is 133 percent or more.
  • Poorly Stocked Stands – Stands in which the stocking of trees is from 16.7 to 60 percent.
Storage Life

The period of time during which a packaged adhesive can be stored under specific temperature conditions and remain suitable for use.

Straw Drum

A small drum on a yarder that handles the straw line.

Straw Line

A light-weight line used to change main skidding lines and tackle in cable yarding systems.


The ability of a member to sustain stress without failure.

Strength Ratio

The hypothetical ratio of the strength of a structural member to that which it has if it contained no strength-reducing characteristics.

Stress Wave Timing

A method of measuring the apparent stiffness of a material by measuring the speed of an induced compression stress as it propagates through the material.

Stress Skin Construction

A construction in which panels are separated from one another by a central partition of spaced strips with the whole assembly bonded so that it acts as a unit when loaded.


A timber or other support for cross members in floors or ceilings.

Structural Composite Lumber (SCL)

Wood elements glued together to form products that are similar in size to solid sawn lumber.

  • Laminated Strand Lumber (LSL) – Similar to oriented strand lumber with somewhat longer strands.
  • Laminated Veneer Lumber (LVL) – Structural composite lumber manufactured from veneers laminated into a panel with the grain of all veneer running parallel to each other. The resulting panel is ripped to common lumber dimensions.
  • Oriented Strand Lumber (OSL) – Structural composite lumber made from wood strand elements similar to those used in oriented strand board. The strands are oriented primarily along the length of the member.
  • Parallel Strand Lumber (PSL) – Structural composite lumber made from high aspect ratio wood strand elements manufactured from veneer oriented primarily along the length of the member. It is manufactured in billets and cut to lumber dimensions.
Structural Integrity

A structure uncompromised ability to safely resist the required loads.

Structural Timbers

Pieces of wood of relatively large size, the strength or stiffness of which is the controlling element in their selection and use.


A short timber placed in a structure either diagonally or vertically; designed to act in compression along the direction of its lengths.


A framing member, usually cut to a precise length at the mill and designed to be used in framing building walls with little or no trimming before it is set in place. Studs are most often 2x4s, but 2x3s, 2x6s, and other sizes are also included in the stub category; studs may be made of wood, steel, or composite material.


The value of timber as it stand uncut in the woods.

Stump Jumper

A heavy plate underneath a skidder that protects the back housing from contact with high stumps.

Stump Pull

Slivers of wood remaining attached to the stump after a tree is felled; the slivers are considered as having been pulled from the butt of the log.


Wood cut into short lengths and piled near the stumps.

Stumpwood Chips

Chips manufactured from Stumpwood.

Style or Stile

A vertical member of a door’s framework attached to the horizontal rails.


A material upon the surface of which an adhesive containing substance is spread for any purpose, such as bonding or coating.


The deck construction that is located below, and supports the deck boards and railing system. Components include joists and hangers, ledgers, rim joists, beams, posts, anchors, and footers.


Logging arch equipment with wheels instead of crawler tracks and towed behind a skidding machine.

Summer Beam

A major horizontal timber which spans the girts or plates.


One of the four major crown classes, specifically trees with crowns entirely below the general level of the crown cover receiving no direct light either from above or from the sides. This is also known as overtopped.

Surfaced Checks

A drying defect that occurs when the surface dries too quickly in relation to the core.

Surface Inactivation

In adhesive bonding to wood, physical and chemical modification of the wood surface that result in reduced ability of an adhesive to properly wet, flow, penetrate, and cute.

Surfaced Lumber

A piece of wood that has been planed smooth on one or more surfaces.

Surface Tension

The force per unit length acting in the surface of a liquid that opposes the increase in area of the liquid.


The way a piece of lumber has been prepared at the lumber mill.

Sustainable Forest Initiative (SFI)

This is a program that was established in 1994 and currently certifies over 152 million acres in the United States and Canada. It is based on the premise that responsible forest practices and sound business decisions can co-exist.
Independent certification bodies evaluate planning, procedures, and processes in the forest and in wood processing operations.

Sustained Yield

Timber yield that a forest can produce continuously at a given intensity of management. Sustained yield management therefore implies continuous production planned to achieve a balance between growth (increment) and harvest at the earliest practical time.


An area saturated with water throughout much of the year, but with the surface of the soil usually not deeply submerged. This is usually characterized by tree or shrub vegetation.

Swamp Buggy

A Skidder equipped with high floatation tires.


A gradual bend in a standing tree or in a log, pole, or piling.


Trees greatly enlarged at the base.


Universal joint used in rigging to prevent lines from twisting.

Symmetrical Construction

Panels in which the plies on one side of a center ply or core are essentially equal in thickness, grain direction, properties, and arrangements to those on the other side of the core.

Lumber Glossary Term Definition

A slot milled in the shape of an upside down “T” to hold special bolts for clamps or jigs.

Table Saw A circular saw mounted under a table with height and angle adjustments for the blade.

The property of an adhesive that enables it to form a bond of measurable strength immediately after adhesive and adherent are brought into contact under low pressure.

Tack Cloth or Tack Rag

A cloth permeated with a sticky substance to wipe up the dust from sanding when finishing a project.

Tack Time The amount of time it takes for an adhesive to set-up before it can form a bond.

The combination of blocks and ropes used in cable logging.

Tagline Extra length of line at the end of a main line. Used as an extension for carrying additional choker hooks or to dampen the swing of a bucket or grapple on a boom-type loader.

The end portion of a birds-mouth joint which extends beyond the plate when there is a roof overhang.

Tail Block A block fixed to a stump at the outer edge of a setting, in ground-lead and high-lead cable logging, or to the tail spar, in skyline cable logging, through which the haul-back line is reeved for returning the main line and the butt rigging to the loading point.

In cable logging, the anchorage at the outer end of the skyline away from the landing. This is also known as a tailholt.

Tail Tree A tree to which the far end of the skyline is attached. This is also known as a tail spar.
Tandems The second axle and set of wheels on the rear of a truck. Live indicates that they are powered; dead that they are not.
Tangential Coincident with a tangent at the circumference of a tree or log, or parallel to such a tangent.

A piece of wood that has been cut so that it is wider on one edge compared to the other.

Taper Cut

The new wood in a tree that lies between the bark and the heartwood. Sapwood is usually lighter in color and becomes heartwood as the tree ages.

Tar Heel

A name given to loggers from any Southeastern state.

Target Forest

A type of forest, in terms of species mixture, size, stocking, and harvest age, considered best for a particular site in order to economically produce fiber in the qualities desires on a perpetual basis.


The tendency for a blade to splinter the last part of a piece of wood during crosscutting.

  • Golden-brown color to darker chocolate-brown
  • Generally straight to wavy grained
  • Hard-medium density
  • Medium bending strength
  • High crushing strength
  • Low stiffness and resistance to shock loads
  • Pre-boring is necessary for nailing
  • Extensively used for ship and boat building, decking, rails, and hatches; furniture, cabinet making, flooring, and garden furniture.
Technical Life Length

The time from which the machine goes into operation until it is no longer used in any operation. Normally, the unit for technical life length is productive time, expressed in hours.

Tempered Hardboard

Dense fiberboard that has been specially treated to increase its durability, strength, density, and moisture resistance.


A pattern. Often a template is made of hardboard and used with a pilot bit to route a shape in a board.

Template Guide

A jig mounted to the bottom of a router that is used to keep the router on the profile of a template when routing with a non-pilot beating bit.

Tenon The projecting end of a timber that is inserted into a mortise.

In an adhesively bonded joint, a uni-axial force tending to cause extension of the assembly, or the counteracting force within the assembly the resists extension.

Tension Wood

Reaction wood that forms on the upper side of a leaning hardwood tree.

Tether Line

A line used to restrain a balloon in flight; such as the line from a logging balloon to the butt rigging.


The size of the cells in wood, described as ranging from coarse to fine; often confused with grain.


A material that will repeatedly soften when heated and harden when cooled.

Thermoset A cross-linked polymeric material.
Thermosetting Having the property of undergoing a chemical reaction by the action of heat, catalyst, ultraviolet light, and hardener, leading to a relatively infusible state.
Thickness Planer

A power-fed rotary planer that trims the surface of a board to a certain thickness.


Cuttings made in immature stands in order to stimulate the growth of trees that remain and to increase the total yield of useful material from the stand.

Thousand Board Feet

A unit of measurement equal to 1,000 feet of wood having a thickness of one inch.

Through Dovetail Joint A method of joining wood where the interlocking pins and tails of the dovetail joint go through the side of its mating piece.
Thumbnail A small rough sketch of the deck and its site.
Tig Welder

An arc welding process that sues a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by a shielding gas, usually an inert gas such as argon, and a filler metal is normally used, though some welds, known as autogenously welds, do not require it.


A method of high-lead cable yarding in which the haul-back line supports the butt rigging and makes it possible to lift the butt rigging and its load over obstacles.

Tilt Blade

A blade that can be tilted in respect to a vertical position.

Tilt Cab

A cab on a machine that is hinged on one side and can be tilted back and lowered for transport.


A general term applied to a forest and its products. Sawed lumber more then 4×4 inches in breadth and thickness.

Timber Appraisal

An economic appraisal of the monetary value of a timber stand.

Timber Frame

A load-carrying structure of timbers ranging in size from 4×4 and up.

Timber Products Output

Timber products cut from roundwood and byproducts of wood-manufacturing plants. Roundwood products include logs, bolts, and other round sections cut from gowning stock trees, cull trees, salvable dead trees, tree on non-forest land, noncommercial species, sapling-size trees, and limbwood. Byproducts from primary manufacturing plants include slabs, edging, trimming, mis-cuts, sawdust, shavings, veneer cores and clippings, and screenings of pulpmills that are used as pulp chips or other products.

Timber Removals
  • Plant Byproducts – Wood products, such as pulpwood chips, obtained incidental to the production of other manufactured products.
  • Plant Residues – Wood material from manufacturing plants not utilized as a product.
Timber Removals from Growing Stock The volume of sound wood in live sawtimber, forest products (including roundwood products and logging residues), and other removals. Roundwood products are logs, bolts, or other round sections cut from trees. Logging residue are the unused portions of cut trees plus unused trees killed by logging. Other removals include growing stock trees removed by cultural operations such as timber stand improvement work and by land clearing and changes in land use.
Timber Removals from Sawtimber

The net board-foot volume of live sawtimber trees removed annually for forest products, including roundwood products and logging residues, and other removals, such as growing stock trees removed by cultural operations, timber stand improvement work, land clearing, and changes in land use.

Timber Stand Improvement

The intermediate thinning of a forest stand, prior to it reaching mature rotation age, generally for the purpose of improving growing conditions or controlling stand composition.

Timber Standing

Timber still on the stump.

Timber Volume
  • Volume of Growing Stock – The volume of sound wood in the bole of sawtimber and poletimber from a stump to a 4-inch minimum top diameter outside bark or to the point where the central stem breaks into limbs.
  • Volume of Sawtimber – The net volume of the saw log portion of live sawtimber in board feet.

The point of the saw blade tooth that digs in and cuts the work piece.


Technical Life Length.

Toe Kick

An indentation designed into the bottom of a cabinet to provide room to allow the user to stand closer to the countertop.

Toggle Clamp

Clamps which can be attached to a base or table to hold work.


A pair of curved arms that pivot like scissors so that a pull on the ring connecting the shorter segments will cause the points on the long segments to bite into the logs. The tongs are activated by the pull on the loading line. Loading tongs without sharp points powered by air or hydraulic cylinders that close on a log.

Tongue and Groove

A joinery method where one board is cut with a protruding “groove” and an identical piece is cut with a matching groove along its edge.

Tooth Back

The read side of a saw blade tooth facing away from the direction of the cut.

Tooth Back Clearance Angle

The angle that measures the amount of space, or clearance between the tooth back and the work piece.

Tooth Face

The front side of a saw blade tooth facing toward the direction of the cut.

Tooth Form

The shape and geometry of a tooth.

Tooth Pitch

The distance between one tooth tip and the next.

Tooth Rake Angle

The angle formed by the tooth face and a line perpendicular to the back of the blade.

Tooth Set

The side to side bending of teeth. Tooth Set if used to widen the cut and prevent pinching of the blade.


To cut off the unmerchantable top of a tree.

Top Lopping

To cut limbs from downed tree tops so that no limbs are more than a specified length along the tree stem.

Top Plate

Attached to the posts and the top rail to support the top rail and balusters. It is also known as the top cap.

Top Rail

The horizontal member installed on the edge; attached to the top of the balusters as well as the posts.


A topographic map. This shows the elevation contours of the ground.

Torpedo Level

A short level used in deck building to set posts plumb. It is sometimes referred to as a canoe level.


The amount of force that is needed to turn an object such as a screw or bolt.

Torque Converter

A centrifugal pump, driven by an engine, that rotates in a case filled with oil.

Torx Head

A screw head requiring a driver in the shape of a star.

Total Tree

A tree with a crown, main stem, and taproot. This does not include the lateral roots.


A quality of wood that permits the material to absorb a relatively large amount of energy, to withstand repeated shocks, and to undergo considerable deformation before breaking.


A steel mast used instead of a spar tree at the landing for cable yarding.

Tracheary Elements

The principal water-conducting elements of the xylem, mostly vessel members and tracheids.


An imperforate wood cell with bordered pits.


A powered vehicle for off-the-road hauling. May be mounted on crawler tracks of wheels. A short wheelbase truck used to haul trailers.


Lifting an entire load of logs from one mode of transportation and placing the logs on another carrier.


A transit level is a means of measuring, or surveying as it is also known, the location, elevation, degree of inclination of any object such as buildings, trees, fences, relative to the placement of the transit.


The walking surface of each step in a stairway.


Wood products infused or coated with any variety of stains or chemicals designed to retard decay, deterioration, fire, or insect damage due to weather.


A woody plant that usually grows to at least 20 feet in height at maturity and commonly has a single trunk with no branches within three feet of the ground.

Tree Classes
  • All Live Trees – Growing stock, rough, and rotten trees one inch in D.B.H and larger.
  • Growing-Stock Trees – Live trees of any size except rough and rotten trees.
  • Poletimber Trees – Live, vigorous, and well-formed trees of commercial species at least 5.0 inches in D.B.H but smaller than sawtimber size.
  • Rotten Trees – Live trees of any size that do not contain a merchantable 12-foot saw log, now or prospectively, because of rot (more than 50 percent of the cull volume of the tree is or will become rotten). Only commercial species are considered.
  • Rough Trees – Live trees of any size that do not contain at least one merchantable 12-foot saw log, now or prospectively, because of roughness or poor form. Only commercial species are considered.
  • Saplings – Live, vigorous, and well-formed trees of commercial species, usually 1.0 to 5.0 inches in D.B.H.
  • Sawtimber Trees – Live trees of commercial species containing at least one 12-foot saw log or two noncontiguous saw logs, each at least eight feet long, and having a maximum allowable defect of 67 percent of the gross tree volume. Softwoods must be at least 9.0 inches in D.B.H. and hardwood at least 11.0 inches in D.B.H.
  • Seedlings – Live trees of commercial species with diameters less than 1.0 inch that are expected to survive (not diseased and not heavily damaged by logging, browsing, or fire). Only softwood seedlings over six inches tall and hardwood seedlings over one foot tall are counted.
  • Short-Log Trees – Sawtimber-sized trees of commercial species that contain at least one merchantable eight-foot to 11-foot saw log (but not a 12-foot saw long).
Tree Farm

A parcel of land on which trees are planted, cultured, managed, and harvested as a crop. Also, privately owned, managed forest area that has been certified as a tree farm by the American Forest Institute.

Tree Farming

The application of silvicultural practices for the perpetual use of commercial timber crops. Includes all activities from stand establishment through delivery of commercial timber (logs) to a log yard at the initial commercial product processing facility.

Tree Length

The entire tree, excluding the Unmerchantable top and limbs.

Tree-Length Logging

Felling and transporting the trimmed bole in one piece, whenever possible, for crosscutting at a landing or mill.

Tree Shoe

A device in the shape of a segment of a circle used to support the skyline from a spar tree.


A framework of thin lumber designed to support climbing plants.


The finish materials in a building, such as moldings, applied around openings or at the floor and ceiling of rooms.

Trim Allowance

Extra length allowed when bucking logs or estimating volume to account for less from end injuries or uneven cuts.

Triple Drum

A three-drum yarder.


Is a woodworking or metal working tool used for marking and measuring a piece of wood. The square refers to the tool’s primary use of measuring the accuracy of a right angle; to try a surface is to check its straightness or correspondence to an adjoining surface.


A traveling block used in a skyline.


Also known as a tree-nail, a turned and tapered hardwood dowel used for securing timber joints.


An assembly of members, such as beams, bars, and rods combined to form a rigid framework. All members are interconnected to form triangles.


Timber Stand Improvement.

  • Heartwood is a beautiful pink-yellow with stripes varying in shades of salmon pink to rose red
  • Straight, but more often irregular grain
  • Moderately fine texture
  • Hard, heavy, compact hardwood
  • Extremely hard to work with
  • Used for turnery, fancy woodenware, cabinets, caskets, jewelry boxes, marquetry, and small decorative items.
Tungsten Carbide

A very common material on any sort of cutting tool. Saw blades, drill bits, and router bits are made of carbide.


An air pump designed to put more air into engine cylinders; pump is driven by the exhaust heat.


Logs yarded in any one top. Load of logs brought in by skidding unit during a single trip, landing to stump and return, made by a tractor or other skidding device.

Turnaround Time

The time it takes for a truck or tractor to be loaded and unloaded.

Try Square

A square with a steel tongue in a wooden handle.


An area of sufficient size, adjacent to a single lane road, that serves as a temporary parking place for vehicles so that oncoming vehicles may pass.

Tusk Joint

Also called a tuck or through tenon; a mortise and tenon joint in which the tenon goes all the way through the corresponding mortise.


Warping in lumber where the ends twist in opposite directions.


“L” skid logs or tree lengths on the without an antifriction device.

Two-Storied Stand

A forest stand in which two height classes of considerable difference occur: the over-story and understory. Does not apply to a forest in the process of reproduction, in which the appearance of two stories is due to a seed tree or shelter-wood cut before the final cut.


A waterproof foam-like substance that forms in the pores of certain species of wood. The Tyloses help to make the wood less permeable to liquids. It is common in White Oak and makes the wood ideal for wine barrels.

Lumber Glossary Term Definition

The brush under a stand of timber.

Undercut A wedge-shaped notch cut in the base of a tree to govern the direction of its fall. This is also known as a box or a notch.

A layer of plywood or other manufactured board used as a base material under finished flooring. Underlayment is often used as a substrate to increase the strength and/or smoothness of the flooring.

Uneven-Aged Management

A Silvicultural system in which individual trees originate at different times and result in a forest with trees of all ages and sizes. Harvest cuts are on an individual-tree selection basis.

Unloaded Deflection The vertical distance between the chord and the unloaded skyline, measured at mid-span.
Unmerchantable Wood Material that is unsuitable for conversion to industrial wood products due to size, form, or quality. May include rough, rotten, and dead trees; the tops, limbs, and cull sections fro, harvested trees; or small and noncommercial trees.
Upper Stem Portion Saw timber tree bole extending from above the merchantable top to as minimum four-inch top diameter outside bark or to the point where the central stems break into limbs.
Utility Knife A cutting tool used in various trades and crafts for a variety of purposes. Designed to be lightweight, easy to carry and use.
Lumber Glossary Term Definition
VanDer Waal Forces

Physical forces of attraction between molecules, which include permanent dipole, induced dipole, hydrogen bond, and Long dispersion forces.

Vapor Retarder A material with a high resistance to vapor movement, such as foil, plastic film, or specially coated paper, that is used in combination with insulation to control condensation.
Variable Costs

Operation costs that result from running a machine, calculated on an hourly basis; includes cost of labor and items such as fuel, oil, wire rope, and replacement parts. Also known as operating costs.

Variable Positive

A tooth form that has variable tooth spacing, standard tooth forms, varying gullet depth, and a zero-degree rake angle.

Varnish A liquid preparation that dries to a hard lustrous coating.
V Joint Tongue and groove boards with their top corners beveled so when the two boards come together a “V” is formed.
Veneer A thin sheet of wood cut from a log; wood peeled, sawn or sliced into sheets of a given constant thickness and combined with glue to produce plywood or laminated-veneer lumber. Veneers laid up with the grain direction of adjoining sheets at the right angles produce plywood of great stiffness and strength; while those that lay up with grains running parallel produce flexible plywood most often used in furniture and cabinetry.
Veneer-Core Plywood Plywood made from three or more pieces of veneer glued up in alternating-grain patterns.
Vessel An axial series of cells that have coalesced to form an articulated tube-like structure of indeterminate length. A union of wood cells which have open ends and are set one above the other, forming continuous tubes. The openings of the vessels on the surface of a piece of wood are usually referred to as pores.
Vessel Elements Wood cells in hardwoods of comparatively large diameter that have open ends and are set one above the other to form continuous tubes called vessels.
Virgin Timber Timber from an original forest that has not been previously disturbed or influenced by human activity.
Viscoelasticity The ability of a material to simultaneously exhibit viscous and elastic responses to deformation.
Viscosity A measurement of the thickness of a liquid.
Void The volume in the wood structure that is not occupied by wood tissue.
Lumber Glossary Term Definition
Wall Decking

Lumber covering the walls; usually 1” tongue-and-groove.

Wane Bark or lack of wood from any cause on edge or corner of a piece except for eased edges.

A defect in lumber characterized by bending in one or more directions; any deviation of the face or edge of a board from flatness, or any edge that is not at right angles to the adjacent face or edge; the most common forms of warp are bow, crook, cup, and twist.

Wash Coat

Typically used as the first coat of a finish. The wash coat is used to change the appearance or porosity of a surface.

Water Level A hose or tube filled with water, used in deck construction to transfer elevations from one post to another. The surface of the water at both ends of the hose must come to rest at the same height, allowing transfer of elevations.
Water Repellent A liquid that penetrates wood that materially retards changes in moisture content and dimensions of the dried wood without adversely altering its desirable properties.
Water Repellent Preservative A water repellent that contains a preservative that, after applications to wood and drying, accomplishes the dual purpose of imparting resistance to attack by fungi or insects and also retards changes in moisture content.
Water Table The upper limit of a saturated zone in the soil.
Wavy A tooth set that has groups of teeth set of one side then the other.
Weathering The mechanical or chemical disintegration and discoloration of the surface of wood caused by exposure to light, the action of dust and sand carried by winds, and the alternate shrinking and swelling of the surface fibers with the continual variation in moisture content brought by changes in the weather.
  • Clearly defined heartwood is dark brown with close, fine black streaks
  • Fairly straight grained with a coarse texture
  • Heavy and dense
  • High bending strength
  • High resistance to shock loads
  • Medium crushing strength and low stiffness
  • Works fairly well with machine tools
  • Used for flooring stripes, interior and exterior joinery, and general construction work.
Wet-Bulb Temperature The temperature indicated by the wet-bulb thermometer of a Psychrometer.
Wetland The transitional area between dry land and aquatic areas having a high water table of shallow water. Land with one of the following three attributes: (1) periodically supports hydrophytes, (2) substrate is predominately un-drained hydric soil, (3) substrate is non-soil and saturated or covered with water during part of the growing season each year.
Wet Strength The strength of an adhesive joint determined immediately after removal from water in which it has been immersed under specific conditions of time, temperature, and pressure.
Wettability A condition of a surface that determines how fast a liquid will wet and spread on the surface or if it will be repelled and not spread on the surface.
White Oak
  • Varies from pale yellow-brown with a pinkish tint
  • Straight grain
  • Medium to coarse texture
  • Medium bending and crushing strength
  • Low stiffness
  • Used for furniture, cabinet making, heavy construction, pews, boat building, wagon bottoms, and coffins.
White Wood Wood products intended for treating, but not yet treated; a designation applied to a number of species such as White Fir.
Whole Tree

All components of a tree, except the stump. This is also known as a full tree.


Wholesale : In the lumber industry in general pertains to orders that are in excess of a 20ft container. Buying wholesale can be a cost effective practice when you are building more than one deck or require the lumber for several projects or even resale. We offer wholesale accounts for all of our products as we are a direct from the mill wholesale hardwood lumber supplier.


In band sawing, the distance from the top of the tooth to the back of the blade.

Winch A steel spool connected to a power source. Used for reeling or unreeling cable. This is also known as drum.
Windfall Tree(s) that have been uprooted or broken off by the wind. This is also known as blow down.
Winding Sticks Two narrow, thin, pieces of material whose edges are perfectly parallel when placed on each end of a work piece. The worker then sights across the top of them to determine if the piece is flat.
Wind Load The lateral pressure on a structure in pounds per square foot, due to wind blowing in any direction.
Windrow A long narrow pile, usually of logging slash removed from a planting site.
Wind Shake Wood cells in hardwoods of comparatively large diameter that have open ends and are set one above the other to form continuous tubes called vessels.
Witness Tree A tree used by surveyors to mark the location of a survey corner; the tree is located near the survey corner and is inscribed with survey data. This is also known as a bearing tree.
Witness Marks These are marks put on boards or pieces to keep them in order during gluing, joining, and assembly.
Wobbly Dado Head A single blade dado cutter where the blade is adjusted to wobble the width of the cut.
Wolf Tree A very large forest tree that has a wide-spreading crown and inhibits or prevents the growth of smaller trees around it
Wood-Based Composite Panel A generic term for a material manufactured from wood veneer, strands, flakes, particles, or fibers or other lignocellulosic material and a synthetic resin or other binder.
Wood Conversion The transformation of natural timber into any kind of commercial product. This includes all activities from commercial timber (log) delivery to the log yard at the initial commercial processing facility to the final product form offered for commercial sale as a consumer product.
Wood Failure The rupturing of wood fibers in strength tests of bonded joints usually expressed as the percentage of the total area involved that shows such failure.
Wood Flower Wood reduced to finely divided particles, approximately the same as those of cereal flours in size, appearance, and texture.
Wood Substance The solid material of which wood is composed. It usually refers to the extractive-free solid substance of which the cell walls are composed.
Wood-Thermoplastic Composite Manufactured composite materials consisting primarily of wood elements and thermoplastic. The wood element may either serve as a reinforcement or filler in a continuous thermoplastic matrix, or the thermoplastic may as a binder to the wood element.
Wood Wool Long, curly, slender strands of wood used as an aggregate component for some particleboards and cement-bonded composites.
Workability The degree of ease and smoothness of cut obtainable with hand or machine tools.
Working Life The amount of time after mixing a glue or paint that it remains useable. Often used when referring to two-part epoxy and polyester glues.
Working Properties The properties of an adhesive that affect or distance the manner of application to the adherents to be bonded and the assembly of the joint before pressure application.
Wormholes Holes and channels cut in wood by insects.
Lumber Glossary Term Definition

The drafting symbol for a cross section of an object.

X-Acto Knife This is a razor like blade in a handle. The blades come in various shapes, and are very handy for fine work.

The cellular tissues inside a tree’s bark; often called wood.

Lumber Glossary Term Definition

The place where logs are accumulated.

Yard Lumber Lumber of those grades, sizes and patterns generally intended for ordinary construction and general building purposes.

A system of power-operated winches used to haul logs from a stump to a landing. This is also known as a donkey.

Yarder Wood

Wood brought into a yard in the form of tree lengths, logs, or bolts, to be cut into shorter lengths.

Yarding of Unmerchantable Material Yarding of cull, rotten, small, or otherwise unusable wood material to be a designated area for disposal is written into the timber contract. This is required on all USDA Forest Service timber sale contracts.
Yarding Road

A path followed by a turn of logs yarded by a cable method.

Yarding Tower

Steel tower used on a steel spar skidder. A light-weight tower built on a tractor.

Yardstick A wooden rule 36” long.
  • Bright yellow heartwood
  • Fine, straight grain
  • Medium texture
  • Work easily with hand and power tools
  • Used for decorative veneer, inlay, and marquetry.
Yield The amount of product output recovered from a quantity of raw material input in forest product industries. Estimate in forest menstruation of the amount of wood that may be harvested from a particular type of forest stand by species, site, stocking, and management regime at various ages.
Yoke The heavy “U”-shaped part of a block by which the pulley is attached.
Lumber Glossary Term Definition
  • Light golden-yellow heartwood with streaks of dark brown to almost black
  • Interlocked grain
  • Coarse texture and lustrous surface
  • Hard, heavy, and stable timber
  • Mainly used for decorative purposes
Zero Clearance Insert A blank insert for a table saw, the blade is raised up through it to create a kerf close to the sides of the blade.
  • Various shades of black heartwood
  • Irregular and wavy grain
  • Carves and turns nicely
  • Non-durable
  • Used for furniture, inlays, and turning.
Zoning Laws

Laws adopted by local governments that restrict the location and type of new construction.