ASTM D1038-19

Standard Terminology Relating to Veneer, Plywood, and Wood Structural Panels

General Information

• Status: Published
• Publication Date: 28-Feb-2019
• ICS: 01.040.79 - Wood technology (Vocabularies)
• ICS: 79.060.10 - Plywood
• Technical Committee: D07 - Wood
• Drafting Committee: D07.03 - Panel Products

Relations

• Replaces: ASTM D1038-11 - Standard Terminology Relating to Veneer and Plywood
• Effective Date: 01-Mar-2019
• Refers: ASTM D5266-13(2020) - Standard Practice for Estimating the Percentage of Wood Failure in Adhesive Bonded Joints
• Effective Date: 01-Apr-2020
• Refers: ASTM D5266-13 - Standard Practice for Estimating the Percentage of Wood Failure in Adhesive Bonded Joints
• Effective Date: 01-May-2013
• Refers: ASTM D1554-10 - Standard Terminology Relating to Wood-Base Fiber and Particle Panel Materials
• Effective Date: 01-May-2010
• Refers: ASTM D1165-07 - Standard Nomenclature of Commercial Hardwoods and Softwoods
• Effective Date: 01-Sep-2007
• Refers: ASTM D1554-01(2005) - Standard Terminology Relating to Wood-Base Fiber and Particle Panel Materials
• Effective Date: 01-Oct-2005
• Refers: ASTM D5266-99(2005) - Standard Practice for Estimating the Percentage of Wood Failure in Adhesive Bonded Joints
• Effective Date: 01-Apr-2005
• Refers: ASTM D1165-03 - Standard Nonmenclature of Domestic Hardwoods and Softwoods
• Effective Date: 10-Jun-2003
• Refers: ASTM D1554-01e1 - Standard Terminology Relating to Wood-Base Fiber and Particle Panel Materials
• Effective Date: 10-Feb-2001
• Refers: ASTM D1554-01 - Standard Terminology Relating to Wood-Base Fiber and Particle Panel Materials
• Effective Date: 10-Feb-2001
• Refers: ASTM D1554-00 - Standard Terminology Relating to Wood-Base Fiber and Particle Panel Materials
• Effective Date: 10-Feb-2001
• Refers: ASTM D5266-99 - Standard Practice for Estimating the Percentage of Wood Failure in Adhesive Bonded Joints
• Effective Date: 10-Apr-1999
• Refers: ASTM D1165-80(1994)e1 - Standard Nonmenclature of Domestic Hardwoods and Softwoods (Withdrawn 2002)
• Effective Date: 01-Jan-1994
• Referred By: ASTM D7031-11(2019) - Standard Guide for Evaluating Mechanical and Physical Properties of Wood-Plastic Composite Products
• Effective Date: 01-Mar-2019
• Referred By: ASTM D1666-22 - Standard Test Methods for Conducting Machining Tests of Wood and Wood-Base Panel Materials
• Effective Date: 01-Mar-2019

Overview

ASTM D1038-19: Standard Terminology Relating to Veneer, Plywood, and Wood Structural Panels establishes a comprehensive set of standardized terms and definitions critical for the wood products industry. Developed by ASTM Committee D07, this terminology standard serves as a definitive reference for professionals involved in the manufacture, specification, and use of veneer, plywood, and structural wood panels. The standard ensures clear, consistent communication by defining terms central to the production, classification, and quality assessment of wood-based panels.

For manufacturers, architects, engineers, builders, and inspectors, ASTM D1038-19 provides essential language to accurately describe materials, processes, panel constructions, and common characteristics encountered with veneer and plywood products. This clarity supports contract documentation, technical communication, and compliance with related product standards.

---

Key Topics

ASTM D1038-19 addresses terminology topics essential to:

• Veneer and Plywood: Definitions for adhesive types, veneer cuts (rotary, quartered, sliced), core construction (lumber core, balanced construction), and panel defects (blister, delamination, checks, blemish).
• Panel Construction: Terms describing structural composition, such as plies, crossbands, matched face arrangements, and core materials (particleboard, MDF).
• Wood Structural Panels: Terminology related to panel classifications like oriented strand board (OSB), composite panels, sheathing, subfloor, and span rating.
• Physical Features and Quality: Descriptions of grain, figure, color variations, natural growth characteristics (knots, burls), defects (gaps, splits, wormholes), and repair methods including patches and synthetic fillers.
• Performance and Use: Terms like moisture resistant adhesive, performance category, span rating, and strength axis, which link directly to structural performance and end-use requirements.

---

Applications

Practical applications of ASTM D1038-19 terminology include:

• Manufacturing and Quality Control: Standardized definitions help ensure consistent product labeling, grading, and quality assessment across the wood products industry for veneer and plywood.
• Specification and Procurement: Architects and specifiers rely on this terminology in construction documents, ensuring specified wood structural panels match desired performance and appearance criteria.
• Regulatory Compliance: Facilitates understanding and application of referenced product standards, such as PS 1 (Structural Plywood) and PS 2 (Performance Standard for Wood-Based Structural-Use Panels), commonly cited in building codes like the International Building Code (IBC) and International Residential Code (IRC).
• Industry Communication: Provides a shared vocabulary for manufacturers, distributors, builders, and inspectors, reducing misinterpretation and disputes regarding wood panel properties or defects.
• Product Development and Testing: Supports precise test reporting for attributes such as adhesive bonds, wood failure, and moisture resistance, critical in third-party certification and research contexts.

---

Related Standards

ASTM D1038-19 references and complements several important standards, including:

• ASTM D1165: Nomenclature of Commercial Hardwoods and Softwoods
• ASTM D1554: Terminology Relating to Wood-Base Fiber and Particle Panel Materials
• ASTM D5266: Practice for Estimating the Percentage of Wood Failure in Adhesive Bonded Joints
• PS 1: Structural Plywood (U.S. Department of Commerce)
• PS 2: Performance Standard for Wood-Based Structural-Use Panels (U.S. Department of Commerce)
• ANSI/HPVA HP-1: American National Standard for Hardwood and Decorative Plywood

By using ASTM D1038-19 alongside these documents, industry professionals ensure full alignment with terminology and classification systems essential to the design, manufacture, and acceptance of plywood, veneer, and wood structural panels.

---

Keywords: veneer terminology, plywood definitions, wood structural panels, ASTM D1038-19, panel construction, OSB, wood-based panels, structural plywood, adhesive, defects, engineered wood.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D1038 − 19
Standard Terminology Relating to
1,2
Veneer, Plywood, and Wood Structural Panels
This standard is issued under the fixed designation D1038; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The terms included in this terminology standard are intended to apply to a family of wood
veneer-basedandwoodstructuralpanelproductsmanufacturedforuseinconstruction,decorative,and
industrial applications.
1. Scope wood and Decorative Plywood
1.1 This standard covers a repository of terms and classifi-
3. Terminology
cations for the business of Subcommittee D07.03.
Veneer and Plywood
1.2 The terms in this standard pertain to processing and
characteristics of wood veneer, plywood, and wood structural
adhesive, n—substance capable of holding materials together
panels.
by surface attachment.
1.3 The values stated in inch-pound units are to be regarded
NOTE 1—Adhesive is the general term and includes, among others,
as the standard. Any SI equivalents provided are approximate.
cement, glue, mucilage, and paste. All of these terms are loosely used
interchangeably. Various descriptive adjectives are applied to the term
2. Referenced Documents adhesive to indicate certain characteristics as follows:
(1) Physical form, that is, liquid adhesive or tape adhesive.
2.1 ASTM Standards:
(2) Chemical type, that is, silicate adhesive or resin adhesive.
D1165 Nomenclature of Commercial Hardwoods and Soft-
(3) Materials bonded, that is, paper adhesive or metal-plastic adhesive,
woods can label adhesive.
(4) Conditions of use, that is, hot-setting adhesive.
D1554 Terminology Relating to Wood-Base Fiber and Par-
ticle Panel Materials
back, n—surface opposite to the face of a panel, or the poorer
D5266 Practice for Estimating the Percentage of Wood
surface of a panel in any grade of plywood calling for a face
Failure in Adhesive Bonded Joints
and back.
2.2 Other Documents:
balanced construction, n—See under construction.
PS 1 Structural Plywood, U.S. Department of Commerce
banding (railing), n—portion of wood or other material
Voluntary Product Standard
extending around one or more edges of a plywood panel.
PS 2 Performance Standard for Wood-Based Structural-Use
Panels, U.S. Department of Commerce Voluntary Product
bleed through, n—adhesive or components of adhesive that
Standard
have seeped through the outer layer or ply of a bonded wood
ANSI/HPVA HP-1 American National Standard for Hard-
product and that show as a blemish or discoloration on the
surface.
1 blemish, n—anything marring the appearance of the veneer
This terminology is under the jurisdiction of ASTM Committee D07 on Wood
and is the responsibility of Subcommittee D07.03 on Panel Products.
that is not classifiable as a defect.
Current edition approved March 1, 2019. Published May 2019. Originally
approved in 1949. Last previous edition approved in 2011 as D1038 – 11. DOI: blending, adj—color change that is detectable at a distance of
10.1520/D1038-19.
6 to 8 ft (1.8 to 2.4 m) but which does not detract from the
These definitions are specific to veneer and plywood. Other definitions relating
overall appearance of the panel.
to timber appear in ASTM Terminology D9, Relating to Wood, Annual Book of
ASTM Standards, Vol 04.10.
blister, n—elevation of the surface of an adherend (separation
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
between plies), somewhat resembling in shape a blister on
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
4 5
AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments, Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1038 − 19
the human skin; its boundaries may be indefinitely outlined component (of ply), n—individual piece of veneer that is
and it may have burst or become flattened. jointed to other pieces to achieve a full length and width ply.
NOTE 3—When the term is used in the context of the face it may also
bolt (veneer), n—short log cut to length suitable for peeling in
be referred to as piece or leaf.
a lathe; also block.
compreg, n—synthetic resin-treated, compressed wood with
bond, n—attachment at an interface between an adhesive and
reduced swelling and shrinking characteristics and increased
an adherend.
density and strength properties.
bond, v—to attach materials together by means of an adhesive.
construction, n—details of assembly or thickness or both, of
borer holes, n—voids made by wood-boring insects. veneers and/or other components used in the fabrication of
plywood.
broken grain (shelling, leafing, grain separation),
all-veneer construction—plywood assembly in which all
n—separation on veneer surface between annual rings.
plies are veneer with ordinarily no single ply of veneer
burl, conspicuous, n—swirl, twist, or distortion in the grain of
exceeding ⁄16 in. (7.9 mm) in thickness.
the wood, usually associated with a knot or crotch, resulting
balanced construction——plywood assembly such that the
in abrupt color variation and/or a cluster of small dark piths
forces induced by uniformly distributed changes in moisture
caused by a cluster of adventitious buds.
content will not cause warpage.
burl, blending, n—swirl, twist, or distortion in the grain of the
composite construction—panel assembly consisting of ve-
wood, usually associated with a knot or crotch, but does not
neers and other wood-based materials.
contain a knot, or abrupt color variation and is detectable at
lumber core construction—hardwood plywood assembly in
6 to 8 ft (1.8 to 2.4 m) as a swirl or roundel.
which the center ply or core is lumber rather than of veneer.
cathedral, n—grain appearance characterized by a series of
symmetrical construction—plywood assembly in which the
stacked and inverted V-shaped grain patterns common in
plies on one side of the panel center line are essentially equal
plain-sliced (flat-cut) veneer (see split heart).
in thickness, grain direction, properties, and arrangement to
those on the other side of the center line.
cauls, n—sheets of material employed singly or in pairs in hot
or cold pressing of assemblies in order to protect either the
core, n—(1) in decorative or hardwood plywood, the inner part
faces or the press platen or both against marring and
of plywood between outer plies, usually veneer, but which
staining, to prevent sticking, to facilitate press loading, or to
may also be sawn lumber (lumber core), particleboard,
impart a desired surface texture or finish, and to provide
medium density fiberboard (MDF), hardboard, or other
uniform pressure distribution.
material, (2) in structural plywood, all plies and layers
between the face and back.
NOTE 2—Cauls may be made of any material such as aluminum,
stainless steel, hardboard, fiberboard, or plastic, with the length and width
NOTE 4—See Terminology D1554 for terms applicable to fiber-based
generally equal to the platen size of the press in which they are employed.
panels such as MDF.
center, n—inner layers whose grain direction runs parallel to
core block, n—in cutting rotary veneer, the portion of the bolt
that of the outer plies; may be of parallel laminated plies.
remaining after available veneer has been removed.
(See also core.)
cross band, n—inner layers of veneer whose grain direction is
characteristic, open, n—checks, splits, open joints, knotholes,
usually perpendicular to that of the face plies, applied
cracks, loose knots, wormholes, gaps, voids, or other open-
particularly to plywood of five or more plies and lumber-
ings interrupting the smooth continuity of the wood surface.
core panels.
characteristic, growth, n—discolorations, pitch streaks and
cross band, v—to place the grain of the inner layer of veneer
knots that naturally occur in wood.
at right angles to that of the face and back.
checks, n—smallslitsrunningparalleltograinofwood,caused
cross bar, n—irregularity of grain resembling a dip in the grain
by strains produced in seasoning and/or by stresses caused
running at right angles, or nearly so, to the length of the
during peeling in a rotary lathe.
veneer.
clipper, n—shearing machine used to dimension dry or green
cross break, n—separation of the wood cells, often appearing
veneers to width.
as barely distinct fine irregular lines across the grain, often
combination core, n—core that includes two or more different due to internal strains resulting from unequal longitudinal
types of wood based material, one of which is reconstituted shrinkage or to external forces.
wood product (see reconstituted wood).
cross figure, n—naturally occurring grain effect characterized
comb grain, n—exceptionally straight grain with closely by mild or dominant patterns across the grain in some faces,
spaced growth increments resembling the appearance of such as the washboard effect that occurs in fiddle-back cross
long strands of combed hair. figure and cross wrinkles that result in a mottle figure.
D1038 − 19
delamination, n—area of a panel where separation of layers softwood, which is produced from trees that are usually
occurred because of failure of the adhesive, either in the needle bearing or coniferous.
adhesive itself or at the interface between the adhesive and
NOTE 5—The term hardwood does not infer hardness in its physical
the adherend.
sense.
discolorations, n—stains in wood substances such as sap
heartwood, n—non-active or dormant center of a tree, gener-
stains, blue stains, from chemical action such as by iron
ally distinguishable from the outer portion (sapwood) by its
coming in contact with the tannic acid of the wood, from
darker color, sometime referred to as heart.
exposure of natural wood extractives to oxygen and light,
impreg, n—wood impregnated with synthetic resin that is
from chemical action of vat treatments or adhesives, and
cured in place so as to reduce swelling and shrinking of the
from surface finishes.
wood on exposure to varying environmental conditions.
dryer, n—kilnorchamber,ormachinethroughwhichthegreen
inner plies, n—plies other than face or back plies in a panel
veneers are passed to remove moisture.
construction such as subface, subback, crossband, and cen-
durability, n—(1) as applied to wood, its lasting qualities or
ter.
permanence in service with particular reference to decay, (2)
interior type plywood, n—term frequently applied to plywood
as applied to the adhesive bond, its resistance to deteriora-
bonded with adhesives that maintain adequate bonds under
tionrelatedtoexposureconditions.(Seealso delamination.)
conditions usually existing in the interior of buildings.
exterior type plywood, n—term applied to plywood that is
joint, n—junction of two adjacent pieces of wood or veneer.
capable of withstanding prolonged exposure to severe ser-
vice conditions including prolonged and repeated wetting adhesive joint—place where two pieces of wood or veneer
without failure in the adhesive bonds; the commercial bond are joined together by means of adhesive.
classification is a function of veneer grade as well as
edge joint—place where two pieces of wood or veneer are
adhesive durability.
joined together edge to edge (joint running parallel to the
grain).
face, n—better surface ply of a panel in any grade of plywood;
also either side of a panel where the grading rules draw no end joint—place where two pieces of wood or veneer are
distinction between outer surfaces. joined together end to end (joint running perpendicular to the
grain) which may be accomplished by a butt joint, scarf joint,
figure, n—pattern produced in a wood surface by annual
or lap joint.
growth rings, rays, knots, deviations from natural grain such
open joint—discontinuity between two adjacent pieces of
as interlocked, curly, and wavy grain, and irregular color-
wood or veneers within a ply (gap).
ation.
starved joint—adhesive joint that is poorly bonded because
fleck, ray, n—portion of a ray as it appears on the quartered or
of an insufficient quantity of adhesive.
rift-cut surface, often a dominant appearance feature in oak.
sunken joint—in the case of plywood, a depression in the
flitch—portion of a log sawed on two or more sides and
surface of the face ply directly above an edge joint in a lumber
intended for remanufacture into sliced or sawn veneer; also
core or crossband, the result of localized shrinkage in the
applied to the resulting sheets of veneer stacked together in
edge-jointed layer.
sequence of cutting.
jointed ply, n—veneer or other components that have ma-
gap, n—open joint or split in the inner plies that results when
chined edges for tightest possible layup.
crossband or center veneers are broken or not tightly butted.
knot, n—crosssectionoftreebranchorlimbwithgrainusually
glue, n—See adhesive.
running at right angles to that of the piece of wood in which
grain, n—direction, size, arrangement, and appearance of the
it occurs.
fibers in wood or veneer.
knot, open—opening produced when a portion of the wood
grain sweep, n—expression of the angle of the grain to the substanceofaknothasdroppedoutorwherecrosscheckshave
long edges of the veneer component over the area extending occurred to produce an opening.
one-eighth of the length of the piece from the ends.
knotholes—voids remaining after removal of knots.
groove, n—decorative face treatment, consisting of narrow knots, blending pin—sound knots ⁄4 in. (6.4 mm) or less that
parallel channels formed into the surface of the panel. generally do not contain dark centers.
NOTE 6—Blending pin knots are barely detectable at a distance of 6 to
gum discoloration, n—gum (resinous material) spots and
8 ft (1.8 to 2.4 m), do not detract from the overall appearance of the panel,
streakscausedbypriorwoodresinaccumulationssometimes
and are not prohibited from appearing in hardwood grades.
found on panel surfaces.
knots, conspicuous pin—sound knots ⁄4 in. (6.4 mm) or less
hairline, adj—very thin line at the joint of two pieces of wood.
in diameter containing dark centers.
hardwood, n—general term used to designate the wood knots, sound, tight—knots that are solid across their face and
producedfromdeciduousorbroad-leavedtreesincontrastto fixed by growth to retain their place.
D1038 − 19
bird peck in pecan and hickory, or pecky in cypress.
knots, spike—knots cut from 0 to 45° to the long axis of
limbs.
peeler log, n—log selected as suitable for cutting into rotary
lap, n—condition in which adjacent veneers overlap one veneer.
another instead of making a smooth edge joint.
platen, n—plate of metal, especially one that exerts or receives
lathe, n—machine on which rotary, half-round, and rift veneer pressure, as in a press used for gluing plywood.
is cut.
plugs, n—straight-sided insertions of sound wood or synthetic
layer, n—single veneer ply, composite core, or two or more
material used to replace defective portions of veneers,
plies laminated with grain direction parallel.
usuallyheldinplacebyfrictionuntilveneersarebondedinto
plywood.
NOTE 7—Two or more plies laminated with grain direction parallel is a
parallel laminated layer.
ply, n—single sheet of veneer, or several components laid with
loose side, n—in knife-cut veneer, the side of the sheet that was
adjoining edges, that may or may not be bonded, which
in contact with the knife as the sheet was being cut, and that forms one lamina in a plywood panel. (See also layer.)
contains cutting checks. (See also tight side.)
NOTE 11—In some constructions, a ply may refer to other wood
components such as particleboard or MDF (see definitions inTerminology
matched veneer, n—arrangement of veneer strips with a
D1554).
particular re
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D1038 − 11 D1038 − 19
Standard Terminology Relating to
Veneer and PlywoodVeneer, Plywood, and Wood Structural
1,2
Panels
This standard is issued under the fixed designation D1038; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The terms included in this terminology standard are intended to apply to a family of wood
veneer-based and wood structural panel products manufactured for use in construction construction,
decorative, and industrial applications.
1. Scope
1.1 This standard covers a repository of terms and classifications essential needed for the business of Subcommittee D07.03.
1.2 The terms in this standard pertain to processing and characteristics of wood veneer and plywood products.veneer, plywood,
and wood structural panels.
1.3 The values stated in inch-pound units are to be regarded as the standard. Any SI equivalents provided are approximate.
2. Referenced Documents
2.1 ASTM Standards:
D1165 Nomenclature of Commercial Hardwoods and Softwoods
D1554 Terminology Relating to Wood-Base Fiber and Particle Panel Materials
D5266 Practice for Estimating the Percentage of Wood Failure in Adhesive Bonded Joints
2.2 Other Documents:
PS 1 Structural Plywood, U.S. Department of Commerce Voluntary Product Standard
PS 2 Performance Standard for Wood-Based Structural-Use Panels, U.S. Department of Commerce Voluntary Product Standard
ANSI/HPVA HP-1 American National Standard for Hardwood and Decorative Plywood
3. Terminology
Veneer and Plywood
adhesive—adhesive, n—a substance capable of holding materials together by surface attachment.
NOTE 1—adhesiveAdhesive is the general term and includes, among others, cement, glue, mucilage, and paste. All of these terms are loosely used
interchangeably. Various descriptive adjectives are applied to the term adhesive to indicate certain characteristics as follows:
(1) Physical form, that is, liquid adhesive, tape adhesive
(2) Chemical type, that is, silicate adhesive, resin adhesive
(3) Materials bonded, that is, paper adhesive, metal-plastic adhesive, can label adhesive
(4) Conditions of use, that is, hot-setting adhesive
(1) Physical form, that is, liquid adhesive or tape adhesive.
(2) Chemical type, that is, silicate adhesive or resin adhesive.
(3) Materials bonded, that is, paper adhesive or metal-plastic adhesive, can label adhesive.
This terminology is under the jurisdiction of ASTM Committee D07 on Wood and is the responsibility of Subcommittee D07.03 on Panel Products.
Current edition approved Nov. 1, 2011March 1, 2019. Published November 2011May 2019. Originally approved in 1949. Last previous edition approved in 20002011 as
D1038 – 83 (2005).D1038 – 11. DOI: 10.1520/D1038-11.10.1520/D1038-19.
These definitions are specific to veneer and plywood. Other definitions relating to timber appear in ASTM Terminology D9, Relating to Wood, Annual Book of ASTM
Standards, Vol 04.10.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1038 − 19
(4) Conditions of use, that is, hot-setting adhesive.
back—back, n—the side reverse surface opposite to the face of a panel, or the poorer sidesurface of a panel in any grade of
plywood calling for a face and back.
balanced constructionconstruction, n——See under construction.
banding (railing)—(railing), n—a portion of wood or other material extending around one or more edges of a plywood panel.
bleed through—through, n—adhesive or components of adhesive that have seeped through the outer layer or ply of a bonded
wood product and that show as a blemish or discoloration on the surface.
blemish—blemish, n—anything marring the appearance of the veneer that is not classifiable as a defect.
blending, adj—color change that is detectable at a distance of 6 to 8 ft (1.8 to 2.4 m) but which does not detract from the overall
appearance of the panel.
blister—blister, n—in plywood, an elevation of the surface of an adherend (separation between plies), somewhat resembling in
shape a blister on the human skin; its boundaries may be indefinitely outlined and it may have burst or become flattened.
bolt (veneer)—(veneer), n—a short log cut to length suitable for peeling in a lathe; also block.
bond, n—the attachment at an interface between an adhesive and an adherend.
bond, v—to attach materials together by means of an adhesive.
borer holes—holes, n—voids made by wood-boring insects.
broken grain (shelling, leafing, grain separation)—separation), n—a separation on veneer surface between annual rings.
burl, conspicuous, n—swirl, twist, or distortion in the grain of the wood, usually associated with a knot or crotch, resulting in
abrupt color variation and/or a cluster of small dark piths caused by a cluster of adventitious buds.
burl, blending, n—swirl, twist, or distortion in the grain of the wood, usually associated with a knot or crotch, but does not contain
a knot, or abrupt color variation and is detectable at 6 to 8 ft (1.8 to 2.4 m) as a swirl or roundel.
cathedral, n—grain appearance characterized by a series of stacked and inverted V-shaped grain patterns common in plain-sliced
(flat-cut) veneer (see split heart).
cauls, n—sheets of material employed singly or in pairs in hot or cold pressing of assemblies being bonded. Cauls are employed
usually in order to protect either the faces or the press platen or both against marring and staining, to prevent sticking, to facilitate
press loading, or to impart a desired surface texture or finish, and to provide uniform pressure distribution.
NOTE 2—Cauls may be made of any material such as aluminum, stainless steel, hardboard, fiberboard, or plastic, with the length and width generally
equal to the platen size of the press in which they are employed.
center—center, n—inner layers whose grain direction runs parallel to that of the outer plies; may be of parallel laminated plies.
(See also core.)
characteristic, open, n—checks, splits, open joints, knotholes, cracks, loose knots, wormholes, gaps, voids, or other openings
interrupting the smooth continuity of the wood surface.
characteristic, growth, n—discolorations, pitch streaks and knots that naturally occur in wood.
checks, n—small slits running parallel to grain of wood, caused by strains produced in seasoning and/or by stresses caused during
peeling in a rotary lathe.
clipper—clipper, n—the shearing machine used to dimension dry or green veneers to width.
combination core, n—core that includes two or more different types of wood based material, one of which is reconstituted wood
product (see reconstituted wood).
comb grain, n—exceptionally straight grain with closely spaced growth increments resembling the appearance of long strands of
combed hair.
component (of ply), n—individual piece of veneer that is jointed to other pieces to achieve a full length and width ply.
NOTE 3—When the term is used in the context of the face it may also be referred to as piece or leaf.
compreg—compreg, n—synthetic resin-treated, compressed wood with reduced swelling and shrinking characteristics and
increased density and strength properties.
D1038 − 19
construction—construction, n—details of arrangementassembly or thickness or both, of veneers andand/or other components
used in the fabrication of plywood.
all-veneer constructionconstruction——plywood assembly in which all plies are veneer. Ordinarily veneer with ordinarily no
single ply of veneer will exceed exceeding ⁄16 in. (7.9 mm) in thickness.
balanced constructionconstruction———a constructionplywood assembly such that the forces induced by uniformly distributed
changes in moisture content will not cause warpage.
composite constructionconstruction——a panel assembly consisting of veneers and other wood-based materials. Normally the
non-veneer component is identified in describing the construction.
lumber core constructionconstruction——hardwood plywood assembly in which the center ply or core is of lumber rather than
of veneer. Ordinarily cores that are ⁄8 in. (9.5 mm) or greater in thickness will be of lumber.
symmetrical constructionconstruction——plywood panelsassembly in which the plies on one side of the panel center line are
essentially equal in thickness, grain direction, properties, and arrangement to those on the other side of the center line.
core—core, n—(1) in decorative or hardwood plywood, the center most ply. It may be of lumber (either edgeglued or closely
assembled) or other wood-based panel material, or of one or more thicknesses of veneer.
(2(1)) in construction decorative or hardwood plywood, the inner part of plywood between outer plies, usually veneer, but
which may also be sawn lumber (lumber core), particleboard, medium density fiberboard (MDF), hardboard, or other material,
(2) in structural plywood, all plies orand layers between the face and back.
NOTE 4—See Terminology D1554 for terms applicable to fiber-based panels such as MDF.
core block—block, n—in cutting rotary veneer, the portion of the bolt remaining after available veneer has been removed.
cross band, n—inner layers of veneer whose grain direction is usually perpendicular to that of the face plies, applied particularly
to plywood of five or more plies and lumber-core panels.
cross band, v—to place the grain of the inner layer of veneer at right angles to that of the face and back.
cross bar, n—irregularity of grain resembling a dip in the grain running at right angles, or nearly so, to the length of the veneer.
cross break, n—separation of the wood cells, often appearing as barely distinct fine irregular lines across the grain, often due to
internal strains resulting from unequal longitudinal shrinkage or to external forces.
cross figure, n—naturally occurring grain effect characterized by mild or dominant patterns across the grain in some faces, such
as the washboard effect that occurs in fiddle-back cross figure and cross wrinkles that result in a mottle figure.
delamination, n—the area of a panel where separation of layers in a laminate occurred because of failure of the adhesive, either
in the adhesive itself or at the interface between the adhesive and the adherend.
discolorations, n—stains in wood substances such as sap stains, blue stains, from chemical action such as by iron coming in
contact with the tannic acid of the wood, from exposure of natural wood extractives to oxygen and light, from chemical action
of vat treatments or adhesives, and from surface finishes.
dryer—dryer, n—a kiln or chamber, or machine through which the green veneers are passed to remove excess moisture.
durability—durability, n—(1) as applied to wood, its lasting qualities or permanence in service with particular reference to decay.
(2(1)) as applied to wood, its lasting qualities or permanence in service with particular reference to decay, (2) as applied
to the adhesive bond, its resistance to deterioration related to exposure conditions. (See also delamination.)
exterior type plywood—plywood, n—a term applied to plywood that is capable of withstanding prolonged exposure to severe
service conditions including prolonged and repeated wetting without failure in the adhesive bonds; the commercial bond
classification is a function of veneer grade as well as adhesive durability.
face—face, n—the better side surface ply of a panel in any grade of plywood calling for a face and back; plywood; also either side
of a panel where the grading rules draw no distinction between faces.outer surfaces.
figure, n—pattern produced in a wood surface by annual growth rings, rays, knots, deviations from natural grain such as
interlocked, curly, and wavy grain, and irregular coloration.
fleck, ray, n—portion of a ray as it appears on the quartered or rift-cut surface, often a dominant appearance feature in oak.
flitch—a portion of a log sawed on two or more sides and intended for remanufacture into sliced or sawn veneer. The term is
veneer; also applied to the resulting sheets of veneer stacked together in sequence of cutting.
gap—gap, n—an open joint or split in the inner plies whichthat results when crossband or center veneers are broken or not tightly
butted.
D1038 − 19
glue, n—See adhesive.
grain, n—direction, size, arrangement, and appearance of the fibers in wood or veneer.
grain sweep, n—expression of the angle of the grain to the long edges of the veneer component over the area extending one-eighth
of the length of the piece from the ends.
groove—groove, n—a decorative face treatment, consisting of narrow parallel channels formed into the surface of the panel; such
as machined.panel.
V-groove—narrow and shallow V- or U-shaped channels machined on the plywood face to achieve a decorative effect.
gum discoloration, n—gum (resinous material) spots and streaks caused by prior wood resin accumulations sometimes found on
panel surfaces.
hairline, adj—very thin line at the joint of two pieces of wood.
hardwood, n—general term used to designate the wood produced from deciduous or broad-leaved trees in contrast to softwood,
which is produced from trees that are usually needle bearing or coniferous.
NOTE 5—The term hardwood does not infer hardness in its physical sense.
heartwood, n—non-active or dormant center of a tree, generally distinguishable from the outer portion (sapwood) by its darker
color, sometime referred to as heart.
impreg—impreg, n—wood impregnated with synthetic resin that is cured in place so as to reduce materially swelling and
shrinking of the wood on exposure to varying environmental conditions.
inner plies—plies, n—plies other than face or back plies in a panel construction. Subface, construction such as subface, subback,
crossband, and center are classed as inner plies.center.
interior type plywood—plywood, n—a term frequently applied to plywood bonded with adhesives that maintain adequate bonds
under conditions usually existing in the interior of buildings; the commercial classification is a function of veneer grade as well
as adhesive durability.buildings.
joint—joint, n—the junction of two adjacent pieces of wood or veneer.
adhesive jointjoint——the place where two pieces of wood or veneer are joined together by means of adhesive.
edge jointjoint——the place where two pieces of wood or veneer are joined together edge to edge (joint running parallel to the
grain).
end jointjoint——the place where two pieces of wood or veneer are joined together end to end (joint running perpendicular to
the grain) which may be accomplished by a butt joint, scarf joint, or lap joint.
open jointjoint——a discontinuity between two adjacent pieces of wood or veneers within a ply (gap).
starved jointjoint——an adhesive joint that is poorly bonded because of an insufficient quantity of adhesive.
sunken jointjoint——in the case of plywood, a depression in the surface of the face ply directly above an edge joint in a lumber
core or crossband. Usually crossband, the result of localized shrinkage in the edge-jointed layer.
jointed—jointed ply, n—veneer or other ply components that have machined edges for tightest possible layup.
knotholes—knot, n—voids remaining after removal of knots.cross section of tree branch or limb with grain usually running at
right angles to that of the piece of wood in which it occurs.
knot, open—opening produced when a portion of the wood substance of a knot has dropped out or where cross checks have
occurred to produce an opening.
knotholes—voids remaining after removal of knots.
knots, blending pin—sound knots ⁄4 in. (6.4 mm) or less that generally do not contain dark centers.
NOTE 6—Blending pin knots are barely detectable at a distance of 6 to 8 ft (1.8 to 2.4 m), do not detract from the overall appearance of the panel, and
are not prohibited from appearing in hardwood grades.
knots, conspicuous pin—sound knots ⁄4 in. (6.4 mm) or less in diameter containing dark centers.
knots, sound, tight—knots that are solid across their face and fixed by growth to retain their place.
knots, spike—knots cut from 0 to 45° to the long axis of limbs.
lap—lap, n—a condition in which adjacent veneers overlap one another instead of making a smooth edge joint.
lathe— lathe, n—the machine on which rotary, half-round, and rift veneer is cut.
D1038 − 19
layer—layer, n—a single veneer ply ply, composite core, or two or more plies laminated with grain direction parallel. Two or more
plies laminated with grain direction parallel is a parallel laminated layer.
NOTE 7—Two or more plies laminated with grain direction parallel is a parallel laminated layer.
loose side—side, n—in knife-cut veneer, the side of the sheet that was in contact with the knife as the sheet was being cut, and
that contains cutting checks. (See also tight side.)
matching—matched veneer, n—in plywood, the arrangement of strips of veneer to obtainveneer strips with a particular repetitive
pattern.
book matchingmatch——turning alternative adjacent face ply arrangement with strips of veneer offrom a flitch common flitch
with alternating strips flipped over.
mismatch—mismatching—making sheets of face veneer from specially selected face ply arrangement with dissimilar (in color
or grain or both) strips of veneer.
reversed matchingmatch, n——turning alternate face ply arrangement with adjacent strips of veneer of a flitch alternated end for
end; also called “swing matching.”swing matching.
slip matchingmatch——laying face ply arrangement with adjacent strips of veneer laid tight side up without turning; also called
“slide matching.”slide matching.
balanced match—face ply arrangement with two or more veneer components or leaves of equal size to make up a single face.
center match—face ply arrangement of veneer components laid with horizontal symmetry.
plank match—face ply arrangement
...