North American softwood (NLGA)

The NLGA (National Lumber Grades Authority) rules define the quality and dimensions of lumber for export.

• Carpentry and structural timber which does not need a grading according to mechanical resistance are graded according to the R list rules.

	Knots	Shakes	Wane	Other imperfections
CLEAR 2 or B CLEAR	4 non-grouped sound knots are tolerated on counter-face and counter-edge	Permitted shake length : 1/2 of the piece's width	Not permitted	Slight drying checks (cracks) - discoloration of heart wood, stain, twisted grain and gum pockets not permitted - Slight sapwood is permitted on 1/4 of the surface
CLEAR 3 or C CLEAR	4 sound knots are tolerated on face and edge. A little more on counter-face and counter-edge	Permitted shake length : the piece's width	Not permitted	Slight drying checks (cracks) - discoloration of heart wood, stain, twisted grain and gum pockets not permitted - Slight sapwood altered
CLEAR 4 or D CLEAR	Not ruled	Permitted shake length : the piece's width	Permitted wane length : the piece's width	Medium discoloration of the heart wood - stains on 10 % of the face and 25 % of the counter-face - 5 gum pockets are permitted - twisted grain permitted

• Timber for further processing, planed on one or two sides, requiring classification according to mechanical resistance for specific uses (wall panelling, skirtings, shelves, carcassing, packing, roofing battens & beams and other structural pieces for common construction) are classified under the NLGA rules.

SELECT Merchantable	For quality structure works, requiring sound, resistant wood of good appearance
No1 Merchantable	For construction, when resistance prevails over appearance
No2 Merchantable	For common construction but without offcuts
No3 Common	For secondary applications such and packaging and pallets

Grade Structural (mechanical classification)
Light Framing	Light mechanical perfomances needed
Select Structural	For construction, when resistance prevails over appearance

Grade Factory
Factory Flitch	For all applications in carpentry and manufacturing of doors, windows, , furniture and small structures. Yields at least 80 % in volume of wood exempt of defects
Shop Flitch	For similar applications as Factory Flitch. Yields at least 60 % in volume of wood exempt of defects
Shop	For sub-products of various widths and shorter lengths

Reference: National Lumber Grades Authority (NLGA - http://www.nlga.org/)