Table 1.
Defect sizes for visual grading for dimensional lumber (ratio to depth)

Defect Categories			No. 1	No. 2	No. 3
Knot	Narrow		≤ 25%	≤ 35%	≤ 45%
	Wide	Edge	≤ 25%	≤ 35%	≤ 45%
		Centre	≤ 30%	≤ 45%	≤ 60%
		Check			≤ 100%	≤ 150%	≤ 200%
	Annual ring width			≤ 6 mm	≤8 mm	Unlimited
Slope of grain			≤ 1/10	≤ 1/8	≤ 1/4