Glossary of Wood Words
A - E
Adhesive: A substance that bonds two other materials together. Commonly referred to as glue.
Air-dried lumber: Boards that have dried naturally by stacking them in the open air, as shown above and right. Air flows between the boards, allowing the moisture in the wood to evaporate. Air drying can take as long as one year per inch of board thickness. In all but the driest regions, moisture content rarely falls below 12 to 20 percent without additional drying indoors.
All-thread: Steel rod (sometimes called drill rod) that has been threaded along its entire length. (Picture a long bolt without its head.) The material comes in a variety of diameters and threads per inch (tpi), and usually measures 36" long. You hacksaw it to any desired length to create everything from custom bolts to adjustment mechanisms for jigs.
Antikickback pawls: Attached to a tablesaw's blade-guard system, these spring-loaded metal plates with sawtooth edges work in conjunction with the splitter. In the event of workpiece kickback, the pawls dig into the wood to prevent it from being propelled toward the operator, shown right.
Apron: A horizontal piece that supports the top or seat and connects the legs of a table or chair.
Arbor: In a tablesaw, the threaded shaft on which the saw blade mounts and is held in place with a nut, shown right. Riding on bearings, the arbor gets rotated by the drive belts to spin the blade. Most saws with 10" blades have a 5/8"-diameter arbor.
Auxiliary fence: A temporary (sometimes sacrificial) fence attached to a tablesaw rip fence or miter gauge, or to some other machine table, or protect a cutter or bit while providing full workpiece support, shown right.
Backer board: A sacrificial board placed behind a workpiece during a cutting or shaping process. The backer board supports the wood to prevent chip-out as the blade or cutter exits the workpiece, shown right.
Bird's eye: Small, circular areas on wood surfaces caused by indented wood fibers.
Biscuit: A common name for football-shape wooden "plates" used in joinery. Made from compressed beech, biscuits fit into slots cut with a biscuit joiner (see right), or a slot-cutting bit in a router. Biscuits increase glue surface in the joint for improved holding power and hold the joint in alignment during clamping. Three traditional sizes (#0, #10, #20) are most common, but several other sizes exist.
Biscuit joiner: A specialized power tool made to cut slots that accept hardwood biscuits. The tool most often resembles an angle grinder with a precision fence and base added on. These parts of the tool work together to align a retractable circular blade that plunges into the mating joint members at the desired slot location. Each plunge creates one half of the biscuit slot.
Blade runout: Runout in circular-saw blades is measured by the amount of side-to-side movement in the blade body.
Blade guard: On a tablesaw, a plastic or metal shroud that covers the blade to prevent the saw operator from placing his hands in contact with a spinning blade. The device also prevents small cutoffs from being thrown toward the front of the tablesaw and the operator.
Board foot: The standard unit of measure for hardwood lumber. Because hardwoods often sell in random widths and lengths, a board foot measures thickness, width, and length to determine the total volume of wood in the board. One board foot is a piece 1x12x12". Use the following formula to calculate the board foot measurement of any piece of lumber.
Bow: A warp in which the ends of a board or wooden member curve in the same direction away from the desired plane, usually along the length.
Burl: A swirling, twisted figure in wood grain caused by growths on the outside of the tree or root.
Burnisher: A round or triangular steel rod with a handle that is used to produce the hooked cutting edge on a cabinet scraper.
Cabinet carcase: The box-like component that is fitted with drawers, shelves, and/or doors in cabinet construction.
Centerline: A layout line drawn at the center of the thickness, width, or length of a workpiece and sometimes marked with the CL symbol. Typically, the centerline marking is used without an accompanying dimensional measurement.
Chamfer: The edge of a board that has been beveled at an angle.
Checks: Splits running along the grain in wood that occur most frequently in end grain.
Chip-out: Splinters of wood that break away from a workpiece during a cutting or shaping process, shown right. Combat chip-out by using sharp blades and bits, backer boards, and slower feed rates.
Clamp blocks: Wedge-shaped blocks temporarily spot-glued to workpieces so that the parts can be clamped together for gluing.
Climb cut: A routing operation during which the router moves in the same direction as the bit's rotation, rather than against the rotation, as is normal. The result is a cleaner, but harder-to-control, cut. Always make light cuts when climb-cutting.
Collet: A metal slotted sleeve that holds
a router bit in place in the router shaft. Secured by a nut, the collet clamps around the shank of the bit.
Many routers come with both 1/4" and 1/2" collets to accommodate available bits, but some inexpensive models are equipped with only a 1/4" collet. Some include a 1/2" collet and a reducer sleeve, as shown, below. Collet styles vary: they typically are not interchangeable between router brands.
Collet runout: The amount of deviation from center (wobble) in a router collet, measured in thousandths of an inch.
Contact adhesive: A thin, rubber-based adhesive, used most often for bonding plastic laminate to substrates. You apply the adhesive to both mating surfaces, then allow it to dry until tacky. When joined, the surfaces bond on contact.
Core: In sheet goods, the layer or layers of material between the face and back veneers.
Counterbore: A stopped hole in a workpiece that allows you to set a screwhead below the surface of the wood. You can plug the counterbore to hide the head, shown right.
Countersink: A shallow, conical hole in a workpiece that matches the shape of a flathead screwhead. When used without a counterbore, it positions the head flush with the surrounding surface, shown above.
Crosscut: A cut across the wood grain.
Cutting Diagram: An illustrated guide that depicts the quantities and sizes of boards required for a project as well as where each part should be laid out to minimize waste. While extremely handy for defining lumber needs, cutting diagrams can't account for grain variations in solid wood stock or sheet goods, or for defects in solid stock. So, use a cutting diagram as a guideline only.
Dado: A square-cornered channel cut across the wood grain, typically using a dado set or a straight router bit, shown right.
Dead-blow hammer: A plastic-bodied hammer with a hollow head that's partially filled with steel shot. When struck against an object, the shot shifts quickly to that end of the head. This transfer of mass prevents the head from bouncing and delivers a solid blow without marring workpieces. Dead-blow hammers are ideal for assembling and disassembling projects.
Dry-fit: Temporarily assembling a project without glue or permanent fasteners. Use this technique to check the accuracy and fit of joinery, and to determine the sequence for final assembly.
Dry time: The amount of time it takes for glue in an assembled joint to completely dry or cure and achieve full strength. This time varies from a few hours to 24 hours, depending on the glue type. Also called cure time.
Ease: To slightly relieve, or "soften," a sharp edge on a piece of wood. This is generally accomplished by sanding, planing, or rounding the edge with a 1/8" round-over router bit.
Edge grain: Wood characterized by the growth rings being 45 or more degrees, preferably perpendicular, to the surface of a board.
Edging: A solid wood strip, usually 1/4" thick or greater, applied to a sheet product, such as plywood, to hide the bare edge. Generally, edging is applied oversize, and flush-trimmed to matching thickness, shown right.
F - R
FAS: An abbreviation used in hardwood-lumber grading for Firsts-and-Seconds: the best boards cut from a log. An FAS board measures at least 6" wide by 8' long, and yields a minimum of 83 percent clear cuttings (areas free of knots and defects), shown above. These areas must be at least 4"x5' or 3"x7'.
Face grain: The pattern made by growth rings in wood on the greatest surface of a board.
False front: A non-structural face applied to a drawer assembly to provide the drawer's finished visible surface, shown right. A false front often is larger than the drawer-box front. Because it is separate from the drawer box, you can adjust the false front, upon assembly, to get the best fit in the drawer opening without repositioning the slides or other drawer hardware.
Feather board: A device made up of a series of narrow fingers that hold a workpiece firmly in position against a machine's table surface or fence, shown right. A feather board helps increase accuracy and improves safety. You can make your own or purchase plastic versions.
Flush-trim router bit: A straight bit with a bearing mounted at the tip, shown right. Typical use includes trimming workpieces--wood or plastic laminate, for instance--to conform to a template or substrate.
Forstner bit: A patented drill bit for sinking holes that does not penetrate all the way through the material. Used for holes requiring a flat bottom.
Grain direction: The direction in which the dominating, elongated fibers or cells lie in the structure of wood.
Green wood: Stock, usually in rough-cut lumber or log form, that has been cut but not dried, and retains a high moisture content. Woodturners often use green stock because of its workability.
Groove: A square-cornered channel similar to a dado, but cut parallel to the wood grain.
Handscrew: A traditional clamp with two long wooden jaws joined by two threaded rods, shown right. The rods adjust independently by turning the handles, which allows you to position the jaws parallel or at angles to one another. Handscrews come in a variety of sizes, based on the length of the jaws (4" to 12"). Throat depth equals half of jaw length
Hardboard: A combination of ground wood pulp and resins pressed into 4 X 8' sheets, typically 1/8" or 1/4" thick. Hardboard comes in three grades: service, standard, and service-tempered (the best choice for shop use), with one smooth face or two, as shown, below. The material often goes by Masonite, the brand name used by one manufacturer.
Another version of this material, known as perforated hardboard (or by the brand name Peg-Board), consists of a 1/4"-thick sheet with 1/8"- or 1/4"-diameter holes drilled at regular intervals. The holes receive hooks that are often used for tool storage.
Hardwood: Wood derived from broadleaf trees--oak, walnut, ash, and cherry, for example. In temperate regions, these trees are deciduous, dropping their leaves annually. Called angiosperms, the trees produce seeds in the form of fruits or nuts. Not all hardwoods are hard and heavy. Balsa, for example, is classified as a hardwood although it contains light, soft wood.
Heartwood: The darker mature wood at the center of a tree.
Hone: To polish and refine a cutting edge by rubbing it against a hard, smooth stone or other surface.
Jig: A device that holds a workpiece or tool so that a woodworking task can be performed efficiently and accurately.
Kerf: The slot or opening produced in a workpiece by a saw blade as it cuts through the material. A standard tablesaw blade cuts a 1/8"-wide kerf.
Kickback: The dangerous mishap that occurs if a spinning blade or bit catches a workpiece and throws it toward the machine operator.
Kiln-dried lumber: Stickered boards dried at an accelerated rate by exposure to warm, dry air inside a chamber called a kiln. By controlling airflow, humidity, and temperature, this process reduces moisture content in just days or weeks to desired levels--6 to 10 percent for hardwoods and high-grade softwoods, 12 to 20 percent for construction lumber.
Length stop: A block of wood fixed in place to serve as a reference point when a number of pieces need to be crosscut to the same length on a radial arm or tablesaw. Also called a stop block.
Magnetic starter: A type of power switch, often used on tablesaws and other large stationary machines. Typically, it contains contact points that are held closed--when the switch operates in the "on" position--by electromagnetic attraction. In the event of a power interruption, the attraction stops, allowing a spring to pull the contacts apart, turning the switch off. This prevents an accidental restart when electrical power returns.
Materials list: A chart accompanying a woodworking project that details every part by letter, name, dimensions, material, and quantity. The list may include notes that indicate special cutting instructions.
Moisture content: The total amount of water in a piece of wood, expressed as a percentage of the wood's over-dry weight. The content can be determined using a moisture meter, shown right. For kiln-dried stock, moisture content generally runs from 4 to 10 percent.
Mullion: A vertical member of a cabinet or door frame that forms a division between two units, such as panels, shown right.
Open time: The amount of time after glue is spread before it becomes unworkable or loses its ability to create a bond. Also called working time. Open time varies depending on temperature, glue type, and humidity. Use the following times as rough guidelines:
- Aliphatic resin (yellow) -- 5-10 min.
- Polyvinyl acetate (white) -- 10-15 min.
- Water-resistant (yellow) -- 5-10 min.
- Polyurethane -- 20 min.
- Epoxy -- 5 min.-12 hrs. (varies by type)
- Liquid hide glue -- 10 min.
Note: Some manufacturers make glues with extended open times. Use these for large or time-consuming glue-ups.
Penetrating finish: A finish, usually wiped on, that soaks into wood pores so that it resides in the wood itself. Tung oil, linseed oil, and Danish oil are examples of penetrating finishes.
Perforated hardboard: The generic name for a 1/4"-thick hardboard sheet with rows of holes spaced at regular intervals. Frequently, this material gets hung vertically and used for tool storage. Often, this material is referred to as Peg-Board -- the brand name of one such product.
Pilot hole: A hole drilled in a workpiece to receive the threaded portion of a screw. The pilot hole is just slightly smaller than the screw's thread diameter.
Pushstick: A safety device used to push a workpiece past a blade or bit during a machining operation while keeping your hands out of harm's way. Make your own or buy commercially made versions, shown right.
Rabbet: An L-shaped channel cut along the edge or end of a workpiece, typically using a rabbeting bit or dado set.
Rail: A horizontal member, most typically in a cabinet's face frame or door, and running between two vertical pieces.
Resaw: Slicing a length of wood with the blade running parallel to the workpiece faces to create thinner pieces. Usually done on a tablesaw or bandsaw, shown right.
Rip: A cut parallel to the wood grain, shown above.
Rough-cut: To cut a workpiece slightly oversize in thickness, width, and/or length, prior to trimming it to final dimensions.
Rough-sawn: Boards--typically hardwoods--cut to thickness, and sometimes width, during the initial milling process. This leaves telltale rough, splintery surfaces on all sides. Does not include planing or reripping.
S - Z
S2S: A lumber-industry abbreviation for "surfaced on two sides". These boards are planed on both faces to final thickness after milling and drying.
Typical S2S Thicknesses (hardwoods):
- Nominal -- Actual
- 4/4 (1") -- 13/16"
- 5/4 (1-1/4") -- 1-1/16
- 6/4 (1-1/2") -- 1-5/16"
- 8/4 (2") -- 1-3/4"
S3S: An abbreviation for "surfaced on three sides". Here, boards get planed on both faces, and then straight-line ripped on one edge, shown right. Most hardwood sells as S3S or S2S.
S4S: An abbreviation for "surfaced on four sides". These boards get planed on both faces, and then ripped on both edges to make them parallel, shown above. Most often, this process produces "dimensional" lumber in standard sizes, such as 1x6, 2x4, and so forth. You'll find softwood construction lumber sold this way, as well as hardwoods in home centers.
Screw pocket: A hole drilled at an angle into a board or piece of sheet goods to allow it to be screwed to another piece of material.
Self-centering bit: A specialized drill bit designed to bore perfectly centered pilot holes for hinge-mounting screws, shown right. The bit uses a standard twist drill inside a retractable spring-loaded sleeve. A tapered end on the sleeve fits into the countersink on a hinge screw hole to automatically center the bit when you press the sleeve against the hinge. Commonly referred to as "Vix" bits (the brand name of the original version), self-centering bits come in various sizes to accommodate different screw gauges.
Set time: The amount of time it takes for glue in an assembly to dry or cure sufficiently for the clamps to be removed. Set time varies depending on temperature, glue type, and humidity.
Use the following times as rough guidelines:
- Aliphatic resin (yellow) -- 30-60 min.
- Polyvinyl acetate (white) -- 30-65 min.
- Water-resistant (yellow) -- 60 min.
- Polyurethane -- 60 min.
- Epoxy -- Varies by type
- Liquid hide glue -- 60 min.
Note: Several manufacturers offer quick-set glues that achieve high tack (stickiness) just after application. Use these for assembling moldings and other difficult-to-clamp projects requiring hurry-up adhesion.
Shank hole: A hole drilled in a workpiece to receive the unthreaded portion of a wood screw's shank. The hole is just slightly larger than the shank diameter.
Slotting cutter: A router bit designed to groove the edges of boards for spline-joint assembly.
Softwood: Wood derived from needleleaf trees--spruce, pine, fir, and cedar, for example. Commonly known as conifers, these trees produce seeds encased in cones, and are also called gymnosperms. Softwood trees are almost always evergreen, retaining their needles year-round. Some softwoods, such as spruce, are soft, but others, such as ponderosa pine, are hard and remarkably strong.
Splitter: A thin vertical plate positioned directly behind a tablesaw blade to prevent the kerf from closing up and pinching the blade during a cutting operation. The splitter can be part of the saw's guard assembly or a separate device.
Spray-mount adhesive: An aerosol glue often used to adhere paper patterns to workpieces. Many types exist; for woodworking, choose the artist's variety, which temporarily bonds well and allows the pattern to peel away, shown right. Always spray the adhesive on the pattern, not the wood.
Squeeze-out: The small bead of glue that gets pushed out of a joint under clamping pressure. Remove this glue by wiping it away, being careful not to spread it, before the glue dries. Or, scrape it off using a chisel or other blade after the glue skins over.
Stile: A vertical member of a cabinet or door frame.
Stopblock: Commonly, this is a small block, clamped or temporarily-affixed to a fence or machine surface. It either holds a workpiece firmly in position, or limits the distance it can travel during machining operations, shown right. Stopblocks also can be attached to a workpiece to limit the movement of a tool, such as a router.
Straight-line ripping: A process for trueing one edge of a board that has no straight edge to work from. A piece of straight-edged lumber is attached along the length of the workpiece and run against the saw's rip fence.
Stretcher: A horizontal piece that connects the lower portions of the legs on a table or chair.
Synthetic steel wool: These flexible abrasive pads are made from thin plastic fibers impregnated with abrasive particles. The fibers are compressed together in a "non-woven" (random) pattern. These pads prove exceptionally useful for sanding woodworking projects, especially between coats of finish. The pads are often referred to as Scotch-Brite pads (the brand name of one such product).You can purchase them from woodworking suppliers in several grits, as shown, below, with their corresponding sandpaper grit or steel wool number.
Thickness planer: A machine used to reduce the thickness of boards, shown right. It features a horizontal rotating cutterhead equipped with knives that shave wood away from the face as the stock passes beneath, driven by infeed and outfeed rollers. The cutterhead and rollers adjust up and down to accommodate different board thicknesses and cutting depths. Stationary thickness planers usually have 15"-wide capacity. Portable benchtop planers handle boards up to 13" wide.
Throat: Most often, the opening in a tablesaw, bandsaw, or router table where the bit or blade protrudes. The throat is usually covered by a removable piece called a throat plate or table insert.
Trunnions: In a tablesaw, the assembly (usually cast-iron) that supports the drive mechanism and controls the blade tilt and elevation. On a cabinet-style saw, shown right, the trunnions usually mount to the trunnion saddle which, in turn, mounts to the saw's cabinet. On a contractor's saw, they mount to the underside of the table.
Turning: The skill of using a lathe; the object make on a lathe.
V-block: A piece of wood with a V-shape groove cut into one face. This device, which is most often shop made, securely holds dowels or other rounded objects in position while drilling.
Zero-clearance insert: A throat plate, used in a tablesaw, with an opening cut by raising a spinning blade or dado set through it, shown right. Because the opening matches the cutting width of the blade, it reduces chip-out by providing maximum workpiece support. It also prevents small pieces from dropping into the throat opening.