PLYWOOD FOR GENERAL USES
Standard of inspection, method of inspection, grades, standards of grades and
methods of determining grades.
A.. Grading:
|
Item
|
Quality
|
a
|
b
|
c
|
d
|
Knot (pin knot is
excluded),bark pocket or pitch pocket
|
Total number of knot,
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 China, 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 ᾿᾿
|
Total number shall not
exceed two multiples of a quotient resulted from dividing the surface area in
sq.ft. For China, 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 ᾿᾿
|
Not limited
|
Not limited
|
Sound knot
|
1/
2 in
. or less of maximum diameter
|
3/
4 in
.or less of maximum diameter
|
2
in
. or less of maximum diameter
|
Not limited
|
Dead Knot
|
1/
8 in
. or less of maximum diameter
|
1/
4 in
. or less of maximum diameter
|
1/
2 in
. or less of maximum diameter
|
1᾿/
2 in
. or
less of maximum diameter
|
Knot Hole
|
1/
8 in
. or less of maximum diameter and it
shall be mended skillfully
|
1/
4 in
. or less of maximum diameter and it
shall be mended skillfully
|
1/
2 in
. or less of maximum diameter and it
shall be mended skillfully
|
1᾿/
2 in
. or
less of maximum diameter
|
Bark Pocket or pitch
pocket
|
1/
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 diameter
|
Not limited
|
Bark Pocket or pitch
pocket
|
1/
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 diameter
|
Not limited
|
Pin Knot
|
It shall not impair
visiblely appearance.
|
It shall not impair
visiblely appearance so remarkably
|
Not Limited
|
Not Limited
|
Discoloration
|
Very Slightly
|
Slight
|
Not conspicuous
|
Not conspicuous
|
Split
|
It shall be filled
skillfully. 1/
32 in
. or
less of width; and length shall not exceed 5 percent of the piece length
|
It shall be filled
skillfully. 1/
16 in
. or
less of width; and length shall not exceed 10 percent of the piece length
|
It shall be filled. 1/
8 in
. or less of width; and length shall
not exceed 15 percent of the piece length
|
1/
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 break
|
None
|
None
|
Length shall not exceed
10 percent of the piece width
|
Length shall not exceed
20 percent of the piece width
|
Worm hole
|
1/
16 in
. or less of maximum diameter. Those
shall be mended skillfully and shall not be clustered
|
1/
8 in
. or less of maximum diameter. Those
shall be mended skillfully and shall not be clustered
|
1/
4 in
. or less of maximum diameter. Those
shall be mended
|
3/
4 in
. or less of maximum diameter. Not
limited for the mended ones
|
False Heartwood
(Applicable only to Beech)
|
Colors shall be well
matched
|
Colors shall be matched
|
Not Limited
|
Not Limited
|
Sound Burl
|
Very Slight
|
Slight
|
Not Conspicuous
|
Not Limited
|
Rough cut , Torn grain,
Brashness
|
3 percent or less of the
surface area, Very slight
|
Do
|
5 percent or less of the
surface area, slight
|
10 percent or less of the
surface area, Not conspicuous
|
Shim
|
Length shall not exceed
10 percent of the piece length, Colors and grains shall be matched. Gap is
not acceptable
|
Colors and grains shall
be matched. Gap is not acceptable
|
Colors shall be matched.
Gap is not acceptable
|
Not Limited
|
Joint
|
Colors and grains shall
be matched in conformity to the condition of joint. Gap is not acceptable.
Joint running slatendicular shall not be conspicuous
|
Colors 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 conspicuous
|
Colors 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
|
Blister
|
None
|
None
|
None
|
None
|
Wrinkle
|
None
|
None
|
None
|
Slight
|
Flaw and depression
|
None
|
None
|
Very slight
|
Not conspicuous
|
Hole (worm hole is
excluded)
|
1/
16 in
. or less of maximum diameter. It
shall be mended skillfully
|
1/
8 in
. or less of maximum diameter. It shall
be mended skillfully
|
1/
4 in
. or less of maximum diameter. It shall
be mended
|
1᾿/
2 in
. or
less of maximum diameter.
|
Finishing
|
Good Finish
|
Do
|
Almost good finish
|
Do
|
Insufficient removal of
tape
|
None
|
Do
|
Do
|
Slight
|
Perforation and other
process (Applicable only to the processed plywood)
|
Good Finish
|
Do
|
Do
|
Not Rough
|
Finishing of transparent
coating which does not obscure the grain or texture.(Applicable only to
plywood finished by transparent coating)
|
Good Finish
|
Do
|
Do
|
|
Other defects
|
Very slight
|
Slight
|
Do
|
Not limited
|
