Wood Terms - A Lumber Glossary from A - Z

Grade-Stamped

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.

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’.

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

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.

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

• 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.

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

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 indicated with official stamp impression.

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

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.

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.

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.

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

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.

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.

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

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

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

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

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

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

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