Plywood For General Uses

Standard of inspection, method of inspection, grades, standards of grades and methods of determining grades.

Grading:
QualityItem
abcd
Knot (Pin Knot is Excluded), Bark Pocket or Pitch PocketTotal Number of Knots, Bark Pocket and Pitch Pocket (Bark Pocket and Pitch Pocket Having 1/8 in. or Less of Maximum Diameter are Excluded)Total number shall not exceed a quotient resulted from dividing the surface area in sq.ft. by 5 sq.ft For Shina, the total number shall not exceed two multiples of above quotient. (If the quotient has any fraction, the quotient shall read as its integer plus “1”)Total number shall not exceed two multiples of a quotient resulted from dividing the surface area in sq.ft. For Shina, the total number shall not exceed three multiples of above quotient. (If the quotient has any fraction, the quotient shall read as its integer plus “1”)Not limitedNot limited
Sound Knot1/2 in. or less of maximum diameter3/4 in.or less of maximum diameter2 in. or less of maximum diameterNot limited
Dead Knot1/8 in. or less of maximum diameter1/4 in. or less of maximum diameter1/2 in. or less of maximum diameter1—1/2 in. or less of maximum diameter
Knot Hole1/8 in. or less of maximum diameter and it shall be mended skillfully1/4 in. or less of maximum diameter and it shall be mended skillfully1/2 in. or less of maximum diameter and it shall be mended skillfully1—1/2 in. or less of maximum diameter
Bark Pocket or Pitch Pocket1/4 in. or less of maximum diameter. Or 1/16 in. or less of width and 3/4 in. or less of length.1/2 in. or less of maximum diameter. Or 1/8 in. or less of width and 3/4 in. or less of length.3 in. or less of maximum diameterNot limited
Pin KnotIt shall not impair sightly appearance.It shall not impair sightly appearance so remarkablyNot LimitedNot Limited
DiscolorationVery SlightlySlightNot conspicuousNot conspicuous
DecayNoneNoneNoneVery Slight
SplitIt shall be filled skillfully. 1/32 in. or less of width; and length shall not exceed 5 percent of the piece lengthIt shall be filled skillfully. 1/16 in. or less of width; and length shall not exceed 10 percent of the piece lengthIt shall be filled. 1/8 in. or less of width; and length shall not exceed 15 percent of the piece length1/4 in. or less of width and length shall not exceed 20 percent of the piece length. But the filled one shall not exceed 1/2 in.of width and length of 25 percent of the piece length.
Cross BreakNoneNoneLength shall not exceed 10 percent of the piece widthLength shall not exceed 20 percent of the piece width
Worm Hole1/16 in. or less of maximum diameter. Those shall be mended skillfully and shall not be clustered1/8 in. or less of maximum diameter. Those shall be mended skillfully and shall not be clustered1/4 in. or less of maximum diameter. Those shall be mended3/4 in. or less of maximum diameter. Not limited for the mended ones
False Heartwood (Applicable only to Beech)Colors shall be well matchedColors shall be matchedNot LimitedNot Limited
Sound BurlVery SlightSlightNot ConspicuousNot Limited
Rough Cut , Torn Grain, Brashness3 percent or less of the surface area, Very slightDo5 percent or less of the surface area, slight10 percent or less of the surface area, Not conspicuous
ShimLength shall not exceed 10 percent of the piece length, Colors and grains shall be matched. Gap is not acceptableColors and grains shall be matched. Gap is not acceptableColors shall be matched. Gap is not acceptableNot Limited
JointColors and grains shall be matched in conformity to the condition of joint. Gap is not acceptable. Joint running slatendicular shall not be conspicuousColors and grains shall be matched in conformity to the condition of joint. Gap shall not exceed 1/64 in. of width and length of 10 percent of the piece length. It shall be mended skillfully. Joint running slatendicular shall be scarcely conspicuousColors and grains shall be almost matched in conformity to the condition of joint. Gap shall not exceed 1/32 in. of width. It shall be mended. Joint running slatendicular shall be scarcely conspicuous.Gap shall not exceed 1/8 in. of width
BlisterNoneNoneNoneNone
WrinkleNoneNoneNoneSlight
Flaw and DepressionNoneNoneVery slightNot conspicuous
Hole (worm hole is excluded)1/16 in. or less of maximum diameter. It shall be mended skillfully1/8 in. or less of maximum diameter. It shall be mended skillfully1/4 in. or less of maximum diameter. It shall be mended1—1/2 in. or less of maximum diameter.
FinishingGood FinishDoAlmost good finishDo
Insufficient Removal of TapeNoneDoDoSlight
Perforation and other process(Applicable only to the processed plywood)Good FinishDoDoNot Rough
Finishing of transparent coating which does not obscure the grain or texture.(Applicable only to plywood finished by transparent coating)Good FinishDoDo
Other DefectsVery slightSlightDoNot limited