Lumber Grade Rules

Lumber Grade Rules

 

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

FAS
FIF
SELECT
#1 COM
#2 & 2B
#3A COM
#3B COM
FAS LIMITS
Minimum Size Board
6″ x 8′
Same as FAS for species being graded
4″ 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′
BETTER FACE TO GRADE FASPOOR FACE TO GRADE #1 COMMON
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.
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 Cuts
SM ——– 4 (4 max.)
SM+1 ——– 3 (5 max.)
SM ——– 2 (7 max.)
Unlimited
Unlimited Sound Cuttings
SM Needed to Take Extra Cutting
6-15′ SM
3-10′ SM
2-7′ SM
Extra Yield Needed for Extra Cutting
SM x 11 91-2/3%
SM x 9 75%
SM x 8 66-2/3%
Special Yields
97% Rule -2 cuts full width any length; Pcs. 6″ & wider with 6-12″ SM SM x 11.64 for Yield
97% Rule On Better Face
2 + 3 SM to be 100% clear or SM x 11 in one cutting on Better Face. 97% Rule
1′ SM-100% 2′ SM SMx 9
1′ SM SMx 8 2A Com- Clear Face Cuttings 2B Com- Sound Cuttings
2A Com on Better Face and reverse side of cuttings sound; will also qualify for 3A Com
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