Specification
Ring porous woods such as red
oak produce two-tiered growth rings
consisting of coarse-textured, darker
appearing early wood (springwood)
and smooth textured, lighter colored
late wood (summerwood).
SPRINGWOOD
SUMMERWOOD
Wind shake or ring shake is a trau-
matic failure of the bonds between
adjacent growth rings caused by an
outside force such as strong wind,
ice, even felling the tree, appear-
ing as a ruptured, feathered, or very
rough texture on a veneer surface.
Worm track results when certain
types of wood cells called paren-
chyma cells multiply to ll voids left
in the cambium as a result of insect
larval activity.
Vine marks are typically isolated,
tightly compacted gure features typi-
cally resulting when an outside force
such as a winding vine compresses
the normal growth pattern in that
region of the tree.
A pin knot with a dark center up to
1/8" in diameter (in most grades) is
called a conspicuous pin knot, and
is limited by the product standard
in grades “AA.” “A,” and “B.”
Inconspicuous pin knots have
no dark center and are not consid-
ered when determining the grade
of a sheet of veneer, as long as
they do not interfere with the over-
all appearance of the face.
A sound knot usually results
when a live limb existed on the
log. It will contain growth rings
like a smaller version of the tree
itself. The knot material is, as the
name suggests, sound, and will
most likely remain
in place throughout the manufac-
turing process.
A solid knot is a cross section of
a limb that was dead when the log
was harvested, usually appearing
as dark in color, likely containing
cracks and bark that are subject to
falling away during manufacturing.
Open knots are permitted on
#2 backs and lower, and on
“C” grade faces and lower, with
some restrictions as outlined in
the product standard.
VINE MARK
WORM TRACK WIND SHAKE SOLID KNOT
PIN KNOT INCONSPICUOUS
PIN KNOT
OPEN KNOT
SOUND KNOT
KNOTS
Hardwood Plywood Grading Guide 2015 columbiaforestproducts.com 15
NOTE: The American National Standard for Hardwood and Decorative
Plywood, ANSI/HPVA HP-1-Current Year is the voluntary product standard
to which most hardwood and decorative softwood plywood is manufac-
tured in North America. Throughout this publication, any use of the word
“standard” is a direct reference to this particular standard. Please see the
introduction to the section on the ANSI/HPVA HP-1-2009 Standard Grading
Tables on page 22 for further clarication.
NATURAL CHARACTERISTICS