Performance Category and Thickness

Performance Category, Panel Thickness and Span Ratings are key categories that need to be considered together.

US PS 1 specifies thickness tolerances and Performance Categories for plywood grades and requires a thickness label in 1000ths of an inch.  We have listed the minimum and maximum allowable panel thickness and recommended thickness label for each relevant Performance Category.

Unsanded, Touch sanded and Overlaid panels

Performance Category3

Thickness Requirements for Unsanded, Touch Sanded and Overlaid Grades1,2

Minimum Thickness inches (mm)

Maximum Thickness inches (mm)

Recommended Thickness Label4 inches

1/4

0.219 (5.56)

0.281 (7.14)

0.225

11/32

0.313 (7.94)

0.375 (9.53)

0.322

3/8

0.344 (8.73)

0.406 (10.32)

0.354

7/16

0.406 (10.32)

0.469 (11.91)

0.418

15/32

0.438 (11.11)

0.500 (12.70)

0.451

1/2

0.469 (11.91)

0.531 (13.49)

0.483

19/32

0.563 (14.29)

0.625 (15.88)

0.578

5/8

0.594 (15.08)

0.656 (16.67)

0.609

23/32

0.688 (17.46)

0.750 (19.05)

0.703

3/4

0.719 (18.26)

0.781 (19.84)

0.734

13/16

0.781 (19.84)

0.844 (21.43)

0.788

7/8

0.831 (21.11)

0.919 (23.34)

0.849

1

0.950 (24.13)

1.050 (26.67)

0.970

1-1/8

1.069 (27.15)

1.181 (30.00)

1.091

1-1/4

1.188 (30.16)

1.313 (33.34)

1.213

Note:1 Thickness requirements are based on a tolerance of 1/32 or ±0.8mm for panels with Performance Categories of 13/16 and less, and ±5% for panels with Performance Categories greater than 13/16. Inch units are presented as primary units due to customary practice in the United States.2Panel thickness measurements are conducted in accordance with procedures set forth in US PS 1 and based on a panel moisture content of 9%.3 Acceptable abbreviations are PERF-CAT, CAT or Category.4  Recommended thickness labels for Performance Categories less than 9/16 are 3% above the minimum.  For Performance Categories greater than or equal to 9/16, the minimum values are those for sanded panels.
Sanded Plywood Panels

Performance Category3

Thickness Requirements for SANDED Plywood1,2

Minimum Thickness inches (mm)

Maximum Thickness inches (mm)

Recommended Thickness Label4 inches

1/4

0.234 (5.95)

0.266 (6.75)

0.234

11/32

0.328 (8.33)

0.359 (9.13)

0.328

3/8

0.359 (9.13)

0.391 (9.92)

0.359

7/16

0.422 (10.72)

0.453 (11.51)

0.422

15/32

0.453 (11.51)

0.484 (12.30)

0.453

1/2

0.484 (12.30)

0.516 (13.10)

0.484

19/32

0.578 (14.68)

0.609 (15.48)

0.578

5/8

0.609 (15.48)

0.641 (16.27)

0.609

23/32

0.703 (17.86)

0.734 (18.65)

0.703

3/4

0.734 (18.65)

0.766 (19.45)

0.734

13/16

0.788 (20.02)

0.837 (21.26)

0.788

7/8

0.849 (21.56)

0.901 (22.89)

0.849

1

0.970 (24.64)

1.030 (26.16)

0.970

1-1/8

1.091 (27.72)

1.159 (29.43)

1.091

1-1/4

1.213 (30.80)

1.288 (32.70)

1.213

Note:1    Thickness requirements are based on a tolerance of ±0.016” (1/64”) or ±0.4mm for specified Performance Categories of 3/4 and less, and ±3% for panels with a Performance Category greater than 3/4. Inch units are presented as primary units due to customary practice in the United States.2   Panel thickness measurements are conducted in accordance with procedures set forth in PS 1 and based on a panel moisture content of 9%.  Acceptable abbreviations are PERF-CAT, CAT or Category4   Recommended thickness labels for Performance Categories are based on the minimum permissible thickness for that category.