Woodworking Glossary

also: growth ring

The visible band of growth in a board's cross-section. One ring equals one year of growth in the tree.

A horizontal rail between table legs that supports the top and ties the legs together. The structural ring beneath a tabletop.

A compressed beech football placed in matching arc-shaped slots cut by a biscuit joiner. Mainly used for aligning panel glue-ups.

also: blotching

Uneven stain absorption caused by varying grain density within a board. Common in cherry, pine, birch, alder, and poplar. Prevented with pre-conditioner, dye, or gel stain.

also: BF, bd. ft.

A unit of lumber volume equal to 1" × 12" × 12", or 144 cubic inches. The standard way hardwood is sold.

also: carcase

The structural box of a cabinet — sides, top, bottom, back — minus doors, drawers, and trim.

also: cabinet scraper

A flat rectangle of spring steel with a burnished burr along the edge. Pulled or pushed at an angle to take fine shavings — especially useful on figured or tearout-prone wood.

A stiff bar (often slightly curved) placed across a glue-up to keep the panel flat under clamp pressure.

also: end checks, face checks

Cracks in the end grain or face caused by uneven drying or rapid moisture change.

also: bench chisel

A handled cutting tool with a flat blade, used to remove waste in joinery and pare surfaces flat.

A precision square with an adjustable head, used for layout, machine setup, and checking joints. The most-used measuring tool in a furniture shop.

A square or rectangular groove cut across the grain of a board, typically to receive a shelf or divider.

also: milling

The process of bringing rough lumber to final flat, square, sized pieces. Usually face-joint, edge-joint, plane to thickness, rip to width.

also: festool domino, loose tenon

A loose tenon made by the Festool Domino system. Oval cross-section, sized to fit a precision-cut mortise.

also: through dovetail, half-blind dovetail

A wedge-shaped pin or tail used to create an interlocking joint that resists pulling apart. The signature joint of drawer construction.

also: draw-bore

A traditional technique where a peg is driven through a tenon and into the mortise at a slight offset, pulling the shoulders tight permanently without clamps.

also: dry assembly, test fit

Assembling joints without glue to check fit before committing to glue-up.

also: aniline dye, TransTint

A finish colorant that dissolves at the molecular level into wood fibers. Penetrates evenly regardless of grain density, giving transparent color even on tight-grained woods.

also: springwood

The lighter, less dense portion of an annual ring, formed in spring when the tree grows quickly.

also: EMC

The MC a board reaches in a given temperature and humidity. Each environment has its own EMC — heated homes drop to 6-8% in winter; humid summers push it to 10-12%.

also: FSP

The moisture content at which wood cell walls are fully saturated but no free water exists. Roughly 30% MC. Wood does not move dimensionally above this point — only below.

also: curl, quilt, birdseye, fiddleback

Decorative patterns in wood beyond plain grain — curl, quilt, birdseye, fiddleback, burl, crotch.

also: plainsawn, plain sawn

A cut where annual rings run roughly parallel to the face of the board. Shows cathedral grain on the face. Cheapest yield from a log; moves most across the face.

also: 4S, foursquare

Lumber that has been milled flat, square, and parallel on all four sides — the goal of the dimensioning process.

A thick, jelly-like stain that does not penetrate deeply. Wipes on and off cleanly, making it a reliable choice for blotch-prone woods like pine, cherry, and birch.

also: glue up, gluing up

The act of assembling and clamping pieces with glue. Often done in stages for complex assemblies.

The direction of the wood fibers along a board's length. Also used loosely to refer to figure or pattern.

Like a dado, but cut with the grain. Used in frame-and-panel construction to hold the panel.

The older, inner wood of a tree, no longer transporting sap. Usually darker and more rot-resistant than sapwood.

also: No. 5

A medium-length hand plane (#5 Stanley), the all-rounder. Handles most dimensioning between scrub work and final smoothing.

also: Janka, Janka scale

A hardness measurement: the force in pounds required to embed an 11.28mm steel ball halfway into the wood. Used to compare species durability.

A machine that flattens one face and squares one edge of a rough board. The first stop in the four-square dimensioning process.

also: try plane, jointing plane, No. 7, No. 8

A long hand plane (#7 or #8 Stanley) used for straightening edges and flattening panels.

The width of material removed by a saw blade during a cut.

also: nitrocellulose lacquer, pre-cat lacquer

A film-building finish (solvent- or water-based) that dries by evaporation rather than cure. Builds quickly, rubs out beautifully, and re-coats blend into earlier coats.

also: half lap, half-lap

A joint where two pieces overlap, each notched to half thickness so the finished joint is flush.

also: summerwood

The darker, denser portion of an annual ring, formed later in the growing season.

also: FAS, select grade, #1 common, NHLA

NHLA hardwood grades. FAS (First and Seconds) is the highest grade with the most clear face. Select is one step down. #1 Common is mid-grade with smaller clear cuttings, usually best value.

also: rays, ray fleck

Ribbon-like cells radiating outward from the pith. Most visible in quartersawn oak as the iconic ray-fleck pattern.

also: MC

The percentage of water in wood by weight. Kiln-dried lumber arrives at 6-8% MC. Wood dimensional changes happen as MC changes.

A rectangular hole cut into one piece to receive a matching tenon from another. The female half of the strongest traditional joint in furniture.

A marking gauge with two adjustable pins, used to score two parallel lines simultaneously for laying out mortises and tenons.

also: nominal

The rough or labeled size of a piece of lumber, not the actual size. A "2x4" is nominally 2"×4" but actually 1-1/2"×3-1/2".

also: working time, pot life

The window of time between applying glue and closing the joint while the glue is still workable. Varies by adhesive.

also: floating panel, frame and panel

A flat board that fits into a frame, often allowed to float in grooves so it can expand and contract with humidity.

also: oil stain, wood stain

A colorant of solid particles suspended in a binder. Particles lodge in pores — works well on open-grained woods like oak; sits unevenly on tight-grained woods like maple.

The very center of the tree's trunk. Wood close to the pith cracks as it dries.

also: thicknesser, thickness planer

A machine (also called a thicknesser) that surfaces a board parallel to its reference face, bringing it to consistent thickness.

also: toe kick

A solid base supporting a piece of furniture — like the base under a cabinet that lifts it off the floor.

also: kreg joint

An angled hole that allows a screw to be driven into an adjoining piece to pull a joint tight. Fast, strong, and forgiving.

also: poly, urethane

A film-building finish (oil-based or water-based) that cures to a tough, plastic-like surface. The most durable common finish; harder to repair than shellac or lacquer.

A cut where annual rings run perpendicular to the face. Shows straight grain and, in oak, dramatic ray fleck. Most stable; expensive yield.

also: rebate

A step cut into the edge or end of a board. Used for case backs, drawer bottoms, and overlay doors.

Shrinkage along the rays — the wide dimension of a quartersawn board. Roughly half the tangential value, making quartersawn the most stable cut.

A horizontal member of a frame.

A cut where annual rings run at 30–60° to the face. Shows straight grain on all four faces, making it ideal for chair and table legs.

also: rubbing out, polishing

The process of leveling and refining a cured finish with progressive abrasives — steel wool, micro-mesh, or rubbing compounds — to control sheen and remove dust nibs.

also: surfaced two sides

Surfaced two sides. The faces of the board are planed; the edges are still rough.

also: surfaced four sides

Surfaced four sides. All four faces of the board are dressed, ready for joinery.

The younger, outer wood that still transports sap. Lighter in color and less durable than heartwood.

also: de-waxed shellac, sealcoat

A finish made from lac resin dissolved in alcohol. Dries fast, repairs easily, sold or mixed in cuts from 1-lb to 3-lb. Excellent as a sealer or as a finish in its own right.

also: smoother, No. 3, No. 4

A short hand plane (#3 or #4 Stanley) used for final surfacing — the last passes before finishing.

A traditional jointing technique that leaves a tiny gap at the center of a panel joint, closed under clamp pressure. Keeps the ends tight even after the panel shrinks.

also: squeezeout

Glue that beads out at a joint under clamp pressure. A small pencil-line bead indicates good coverage and pressure.

A vertical member of a frame, such as the outside upright of a cabinet door.

A horizontal piece running between table or chair legs, set lower than aprons. Provides extra rigidity to the base.

Shrinkage across the annual rings — the wide dimension of a flatsawn board. Always greater than radial shrinkage; usually about twice as much.

also: chipout, chipping

Wood fibers ripped out below the surface by a blade or plane cutting against the grain direction. Often impossible to sand out — must be scraped or planed in the correct direction.

A projecting tongue cut on the end of one piece, sized to fit a matching mortise. The male half of a mortise-and-tenon joint.

also: sealer coat, seal coat

A thinned coat of finish (often 1-lb shellac) used to seal pores before staining or between finish coats. Reduces blotch and improves topcoat adhesion.