Click here for some amazing Hardwood Facts:
Standard industry practice to express wood thickness in quarters of an inch
(i.e. 5/4" = 1 1/4")
A patch of distorted grain resulting from birds pecking
Small decorative circular figure, common in hard maple and brazilian cherry
A piece of lumber 1 inch thick, 12 inches wide, and 1 foot long
A swirl or twist in the grain of wood which does not contain a knot
100 lineal feet.
A lengthwise seperation in the wood surface caused by rapid or faulty seasoning.
Wood with narrow growth rings.
Most woods darken after finishing if not constantly exposed to the sun's rays. (Walnut is an exception.)
A convex board with one or both edges higher than center.
Disintegration of wood substance due to the action of wood-decaying fungi.
The most common defects includes knots, worm holes, bird peck (bark pockets), wane, stain, pitch, checks, unsound burls, shake and split.
Lumber cut, or S4S, to predetermined specific width (sometimes also to length.)
Seperation of the wood fibers at the end of a board.
Lumber grain as seen from one end of the board.
Tongue and grooved on the ends of boards as well as the sides ( as in Oak flooring).
Obtaining the same moisture content from board to board in a charge or lumber
A grain characteristic that has a rippled appearance. (Maple, Mahogany, and Sycamore)
Unusual wood grain patterns.
Freshly sawn; Unseasoned.
New wood formed by the annual growth of a tree. (Also called annual rings)
The central supporting column of the tree trunk, consisting of matured wood in which little further change will occur.
The cellular seperation that occurs in the interior of a board, usually along the wood rays.
The path that any saw makes in the process of cutting.
A board one foot in length, regardless of width or thickness.
One thousand board feet.
Radial vertical tissues, extending across the growth rings of a tree, that enable the transmission of sap and produce a decorative spotted figure in quartersawn boards.
Lumber that has been manufactered by being run through such milling machines as a planer, straight line rip, etc.
An olive to greenish-black or brown discoloration of undetermind cause in hardwoods.
Percentage or moisture present in wood; degree of dryness.
Actual size of finished lumber.
National Hardwood Lumber Association, P.O. Box 34518, Memphis, Tennessee 38134
1 x 4 . . . . 1 x 5 . . . . 1 x 6 . . . . etc.
A resinous, gummy substance in firs and pines.
Defects resulting from resin accumulated between the growth rings in softwoods.
The small soft center core of a tree around which growth takes place.
Lumber sawn together to the tree's annual rings. Most lumber is Plain Sawn. Advantages in plain Sawing: 1. Less costly and wasteful, hence more available; 2. Easier to kilm dry; 3. Averages wider widths.
In commercial practice, lumber cut with rings (see either end of the board) at angels or 45 degrees to straight up 90 degrees i.e. parallel or almost with medullary ray. In oak it produces spotted figure; in mahogany a ribbon-stripe. Advantages in Quarter Sawing: Shrinks, twists, cups, checks, and splits less.
The fact that hardwoods are almost always offered in a random width and length assortment can present something of a mystery. The question: "Why aren't Birch, Oak, and Walnut produced in convenient dimension sizes like Pine, Redwood and Fir?" Answer: hardwood lumber is cut to yield the maximum of usable material and minimize waste. Both widths and lengths are, therefore, random and even the best grades allow for occasional defects.
Rift sawing is midway between quarter-sawing and plain sawing. It offers the same figure consitency as quarter-sawing but develops a more subtle grain figure.
The board as it comes from the saw. Not surfaced.
Striaght-Line ripped one edge to give one true glue edge.
Surfaced (machines to a smooth finish) on two sides; edges are rough.
Surfaced (machined to a smooth finish) on all four sides.
Sap no defect.
The lighter-colored wood growing between the heartwood and bark.
A tree which is spared during the lumbering process for the purpose of providing a source of seed for restocking the cut-over area.
The practice of only cutting mature trees for lumber.
A lengthwise seperation of wood, occuring before the timber is cut into lumber, usually resulting from violent storms or in felling the log.
High-Quality lumber shorter than standard grade. (Less than 6 feet long)
Decrease in the volume or dimension of wood as a direct result of the drying process. Greatest in hardest woods. Plain sawn boards will usually shrink twice as much as quarter-sawn.
Discoloration in the lumber cause by decay, fungi, etc. Normally avoidable through proper handling in the cutting and drying stages. Also, a finishing substance for coloring wood.
This term refers to a special process in which the green lumber (usually Walnut or Cherry) is steamed in vats for the purpose of darkening sapwood to blend with heartwood color.
The board's principle wood grain runs parallel to it's length.
Produces a perfectly straight edge which is ready for gluing.
The seperation of the wood fibers, producing small, shallow, length-wise serperation of wood along the board's surface.
A record of the number of pieces and footage by grade.
Judgemental decisions for acceptable "give or take" variance from rules and dimension specifications.
Tongue and grooved on sides of board so that the tongue edge of one board fits into the gooved edge of the next board.
Tongue and grooved on both sides and at both ends of piece, as in oak flooring.
A defect in which fibers below the dressed surface are torn by the planer or cutters.
Spiral warpage of board.
The presence of bark, or the lack of wood from any cause, on the edge or corner of a piece of lumber.
Short length (3' high) wall paneling.
Distortion in whish board turns or twists out of shape. Especially prevalent in woods of uneven density, e.g., spawood and heartwood of contrasting hard-soft annual growth. Also results from applying finishes, veneers, laminated plastics, etc. to one side of the piece only.
Worm Holes a defect.
Worm holes no defect.
Voids in the wood cause by the burrowing action of certain wood infesting worms, which do not survive the kiln-drying process.