Domestic Plywood Grades

Veneer Cuts

Plain Sliced
Plain slicing a log occurs when a log is only turned a few inches at a time when slicing it, versus a constant turn and peeling method used for Rotary Cut veneer. Plain Sliced veneer produces a cathedral grain pattern, similar to the pattern produced when plain sawn lumber is produced. Plain Sliced veneer is cut along the growth rings, producing the highest yield of any “slicing” method.

Rotary
Rotary is the process of peeling the entire long. Turning the log, while shaving the veneer as it turns produces Rotary Cut veneer. This process is the only cutting method that is capable of producing whole piece face veneers. Rotary cut will yield veneer with a broad grain pattern with no plain sliced or quartered appearance. Rotary cut veneers are used in the majority of panels produced in North America. This process yields the most veneer per log and is usually less expensive than sliced veneer.

Domestic Plywood Grade Rules

Face Grades		A Grade	B Grade	C Grade	D Grade
Birch, Ash, Maple and Poplar: Rotary-Cut, Plain-Sliced
Pin Knots and Small Burls, Comb. Avg.	ANSI	10- 4 to 1/4"	16- 8 to 1/4"	No Limit	No Limit
Conspicuous Burls, Max.	ANSI	3/8"	1/2"	No Limit	No Limit
Sound and Repaired Knots in Comb	ANSI	No	4	8	10
Repaired Knots	ANSI	No	4 to 1/8"	4 to 1/2"	5 to 3/4"
Mineral Streaks	ANSI	Slight	Slight	Yes	Yes
Vine	ANSI	Slight	Yes	Yes	Yes
Rough Cut	ANSI	No	Slight	Two 8" Areas	5% of Panel
Blended Repaired Tapering Hairline Splits	ANSI	Two 1/16" x 6"	Four 1/8" x 8"	Four 3/16" x 8"	Six 1/4" x 10"

Face Grades		A Grade	B Grade	C Grade
Red and White Oak: Rotary-Cut, Quarter-Cut, Plain-Sliced
Pin Knots and Small Burls, Comb. Avg.	ANSI	12- 10 to 1/4"	24- 16 to 1/4"	No Limit
Sound and Repaired Knots in Comb	ANSI	No	4	8
Repaired Knots	ANSI	No	4 to 1/8"	4 to 1/2"
Mineral Streaks	ANSI	Slight	Few to 8"	Yes to 12"
Sap	ANSI	5%	Up to 20%	Yes
Blended Repaired Tapering Hairline Splits	ANSI	Two 1/16" x 6"	Four 1/8" x 8"	Four 3/16" x 8"

Back Grades		1 Back	2 Back	3 Back	4 Back
Sound Tight Knots	ANSI	16 to 3/8"	16 to 3/4"	Max 16 1/2"-1 1/2	Yes
Knotholes	ANSI	No	All Repaired	All 3/8" 10 to 1	Up to 4"
Repaired Knots	ANSI	No	8 to 1/2"	Not	No
Sound Tight Burls	ANSI	Yes	Yes	Yes	Yes
Mineral/Sap	ANSI	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes
Rough Cut	ANSI	Two 8" Dia. Areas	Yes	Yes	Yes
Joints or Splits	ANSI	Six 1/8" x 12" Rep’rd	Six 3/16" x 12” Rep’rd	3/8" x 1/4" LOP	1" to 1/4 LOP, 1/2" to 1/2 LOP, 1/4" to Full LOP

Core Descriptions

Combination Core
There are two types of Combination Core construction. The first type consists of a center veneer core and a crossband veneer on both sides of the center with a layer of MDF, particleboard, or hardboard under the face and back veneer. The second type consists of an oriented strand board or wafer board center with a veneer crossband on both sides, under the face and back veneer.

Lumber Core
Lumber edge glued into a solid slab is considered Lumber Core. Lumber Core plywood is most often found in the construction of import panels, usually only 18mm thickness panels. Lumber Core plywood consists of a face & back veneer, then a layer of crossband veneer, with the edge glued lumber in the center.

MDF Core
Medium Density Fiberboard Core has the most uniform thickness and consistency of any panel core. The face and back veneer are glued directly to the MDF Core without the need for a crossband veneer.

Particleboard Core
Particleboard Core panels are constructed similar to MDF Core panels, with the face & back veneers glued directly to the core. Particleboard Core lays flat like MDF, but does not have the screw-hold strength of other cores.

Veneer Core
Veneer Core plywood consists of a center veneer and crossband veneers alternately layered on both sides of the center to the desired thickness producing an odd number of veneers for the core.