51.2280—Tolerances for grade defects.

(a) All percentages shall be claculated on the basis of weight.
(b) In order to allow for variations, other than for color and size, incident to proper grading and handling, tolerances shall be permitted for the respective grades as indicated in Table I:
Table I
[Percent]
Grade Tolerances for grade defects
Total defects Serious damage Very serious damage Shell and foreign material
U. S. No. 1 5 2 (included in 5 percent total defects) 1 (included in 2 percent serious damage) 0.05 (included in 1 percent very serious damage).
U.S. Commercial 8 4 (included in 8 percent total defects) 2 (included in 4 percent serious damage) 0.05 (included in 2 percent very serious damage).