Thickness Tolerance Of Plywood & Number Of Plies

Different factories produce plywood in different ways . For example, some factories’ 4mm plywood is 3 plies, but some factories’ 4mm plywood is 5-ply .

Thickness No. of plies     Sanded Plywood    Unsanded Plywood
(mm)            (mm)
3.0 mm    3 plies            + 0.3/-0.4         + 0.4/-0.3
4.0 mm    3 plies (or 5 plies)   + 0.3/-0.5         + 0.8/-0.4
6.5 mm    5 plies            + 0.4/-0.5         + 0.9/-0.4
9.0 mm    7 plies            + 0.4/-0.6         + 1.0/-0.5
12.0 mm   9 plies            + 0.5/-0.7         + 1.1/-0.6
15.0 mm 11 plies            + 0.6/-0.8         + 1.2/-0.7
18.0 mm 13 plies (or 15 plies) + 0.7/-0.9         + 1.3/-0.8
21.0 mm 15 plies (or 17 plies) + 0.8/-1.0         + 1.4/-0.9
24.0 mm 17 plies (or 19 plies) + 0.9/-1.1         + 1.5/-1.0
27.0 mm 19 plies (or 21 plies) + 1.0/-1.2         + 1.6/-1.1
30.0 mm 21 plies (or 23 plies) + 1.1/-1.3         + 1.7/-1.2