Lumber Grades

This chart summarizes the main requirements for the standard grades. For complete information, consult the appropriate section of the NHLA Rule Book.

Minimum Board6" X 8'Same as FAS for species being graded4″ x 6′3" x 4'3" x 4'3" x 4'3" x 4'PITH= SM in inchesWane= 1/2 Length Knot= 1/3 SM Warp= Entire board must be flat enough to S2S to S.S.T. Splits: not to exceed 2 x SM or 12″ whichever is greater. Splits shall not diverge 1″ in 12″ First Lineal Foot Rule: Applies to both ends of Board, to contain not over 25% unsound wood.Wane in FASIFACE: FAS transmission applies to better face.#1 Common Side: 1/3W or 1/2L Widest wane added together: Length can be on both edges.
Minimum Size Cutting
4″ x 5′ 3″ x 7′
4″ x 2′ 3″ x 3′
3″ x 2′
3″ x 2′
Not less than 1 1/2″ wide containing 36 sq. inches
Wane in Selects: Pcs. 6″ & Wider FAS limitation applies to Better face.#1 Common side: 1/3W or 1/2L Widest wane added together. Length can be on both side. Pcs. 4″ & 5″ Wide 1/3W or 1/2L applies to both faces. Add widest wane together. Add total length of wane from both edges.
Minimum Size Cutting4″ x 5′ 3″ x 7′BETTER FACE TO GRADE FASPOOR FACE TO GRADE #1 COMMON4″ x 2′ 3″ x 3′3″ x 2′3″ x 2′Not less than 1 1/2″ wide containing 36 sq. inches
Basic Yield SM x 10 83-1/3%SM x 8 60-2/3%SM x 6 50%SM x 4 33-1/3%
SM x 3 25%
Formula to Determine Number of CutsSM ——– 4 (4 max.)SM+1 ——– 3 (5 max.)SM ——– 2 (7 max.)UnlimitedUnlimited Sound Cuttings
SM Needed to Take Extra Cutting6-15′ SM3-10′ SM2-7′ SM
Extra Yield Needed for Extra CuttingSM x 11 91-2/3%SM x 9 75%SM x 8 66-2/3%
Special Yields97% Rule -2 cuts full width any length; Pcs. 6″ & wider with 6-12″ SM SM x 11.64 for Yield97% Rule On Better Face2 + 3 SM to be 100% clear or SM x 11 in one cutting on Better Face. 97% Rule1′ SM-100% 2′ SM SMx 91′ SM SMx 8 2A Com- Clear Face Cuttings 2B Com- Sound Cuttings2A Com on Better Face and reverse side of cuttings sound; will also qualify for 3A Com