Plywood quality control and grading standards A standard beyond the standard

A standard beyond the standard

Orignal Source ,https://www.columbiaforestproducts.com/hardwood-plywood-overview/

ANSI/HPVA defines hardwood plywood as “a panel composed of an assembly of layers or plies of veneer or veneers in combination with lumber core, particleboard core, MDF core, hardboard core, or of a special core material joined with an adhesive. Except for special constructions, the grain of alternate plies is at right angles and the face veneer is a hardwood species.”

Specifications
Species : various
Face grades : A,B,C,D,E
Back grades : 1,2,3,4
Sizes : 4×6, 4×7, 4×8, 4×10, 5×8, 8×4
Thickness : 1/8″ to 1-1/4″
Core types : JayCore®, KayCore®, veneer core, particleboard core (PBC), medium density fibercore (MDF), combination core, Classic Core®, lumber core

Comparison of Face Grades

Birch, Ash, Maple and Poplar:
Rotary-Cut, Quarter-Cut, Plain-Sliced

A Grade B Grade C Grade D Grade
Pin Knots and Small Burls, Combined Avg. Columbia 6 to 3/32″ 6 to 1/4″ Scattered 15 per 4×8 panel
ANSI 10 – 4 to 1/4″ 16 – 8 to 1/4″ No limit No limit
Conspicuous Burls, Max. Columbia 3/8″ 1/2″ No limit No limit
ANSI 3/8″ 1/2″ No limit No limit
Sound and Repaired Knots in Combination Columbia No 4 6 7
ANSI No 4 8 10
Repaired Knots Columbia No 4 to 1/8″ 2 to 1/4″ 3 to 3/4″
ANSI No 4 to 1/8″ 4 to 1/2″ 5 to 3/4″
Mineral Streaks Columbia Slight Slight Yes Yes
ANSI Slight Slight Yes Yes
Vine Columbia Slight Yes, with grain Yes, with grain Yes
ANSI Slight Yes Yes Yes
Rough Cut Columbia No Two 5″ areas Two 8″ areas 5% of panel
ANSI No Slight Two 8″ areas 5% of panel
Blended Repaired Tapering Hairline Splits Columbia Two 1/16″x6″ Two 1/8″x8″ PPE* Two 3/16″x8″ PPE* Two 3/16″x10″ PPE*
ANSI Two 1/16″x6″ Four 1/8″x8″ Four 3/16″x8″ Six 1/4″x10″

 

Comparison of Face Grades

Red and White Oak: Rotary-Cut, Quarter Cut, Plain-Sliced

A Grade B Grade C Grade
Pin Knots and Small Burls, Combined Avg. Columbia 6 to 3/32″ 6 to 1/4″ Scattered
ANSI 12 – 4 to 1/4″ 24 – 8 to 1/4″ No limit
Sound and Repaired Knots in Combination Columbia No 4 6
ANSI No 4 8
Repaired Knots Columbia No 4 to 1/8″ 2 to 1/4″
ANSI No 4 to 1/8″ 4 to 1/2″
Mineral Streaks Columbia Slight Few to 8″ Yes to 12″
ANSI Slight Few to 8″ Yes to 12″
Sap Columbia 5% Up to 20% Up to 25%
ANSI 5% Up to 20% Yes
Blended Repaired Tapering Hairline Splits Columbia Two 1/16″ x 6″ Two 1/8″ x 8″ PPE* Two 3/16″ x 8″ PPE*
ANSI Two 1/16″ x 6″ Four 1/8″ x 8″ Four 3/16″ x 8″

* PPE – Per Panel End
No Sap Allowed in Rift, Comb. and P/S; Allowed in Rot. Wh. Oak
Rot. Red Oak; 10% Sap Allowed in Rift, Comb, and P/S; Any Sap Allowed in Rot. Wh. Oak

Comparison of Back Grades

1 Back 2 Back 3 Back 4 Back
Sound tight knots Columbia 8 to 3/8″ 8 to 3/4″ Max 15 1/2″ – 1-1/2″ Yes
ANSI 16 to 3/8″ 16 to 3/4″ Max 16 1/2″ – 1-1/2″ Yes
Knotholes Columbia No All Repaired All Repaired Up to 4″
ANSI No All Repaired All 3/8″ 10 to 1″ Up to 4″
Repaired Knots Columbia No 3 to 1/2″ 5 to 1″ No
ANSI No 8 to 12″ No No
Sound tight burls Columbia Yes Yes Yes Yes
ANSI Yes Yes Yes Yes
Mineral/Sap Columbia Yes/Yes Yes/Yes Yes/Yes Yes/Yes
ANSI Yes/Yes Yes/Yes Yes/Yes Yes/Yes
Rough Cut Columbia Two 8″ Dia. areas Yes Yes Yes
ANSI Two 8″ Dia. areas Yes Yes Yes
Splits or Joints Columbia Two 1/8″ x 8″ PPE* Three repaired Splits
3/16″ x 10″ PPE*
Three repaired Splits
3/8″ x 12″ PPE*
1″ to 1/4 LOP*,
1/2″ to 1/2 LOP*, 1/4″ to Full LOP*
ANSI Six 1/8″ x 12″ repaired Six 3/16″ x 12″ repaired 3/8″ x 1/4 LOP* 1″ to 1/4 LOP*, 1/2″ to 1/2 LOP*, 1/4″ to Full LOP*

* PPE – Per Panel End, LOP = Length of Panel
May be obtained repaired, if specified

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