List of Number of Plies/Layers for plywood in each thickness:
| Thickness (mm) | No. of Plies of Commercial Plywood |
| 2~3.2 | 3 |
| 3.6 | 3 or 5 |
| 4 | 5 |
| 5.2~6.5 | 5 or 7 |
| 9 | 7 or 9 |
| 12 | 9 or 11 |
| 15 | 11 or 13 |
| 18 | 13 or 15 |
| 21 | 15 or 17 |
| 24 | 17 or 19 |
| 27 | 19 or 21 |
Minimum Number of Plies in Plywood
As shown in the table, the minimum number of plies in plywood is 3 plies. An odd number of plies in plywood can reduce warping and deformation . Plywood with 1 ply and 2 plies will warp and twist .
The Laws of No. of Plies in a Plywood
1. If the thickness of plywood increase 3mm, the No. of Plies will increase 2 plies;
2. The plywood made of more plies is stronger than the plywood of same thickness but made of less plies. For example, 18mm plywood of 15 plies is stronger than 18mm plywood of 13 plies.
3. The plywood made of more plies is more expensive than the plywood of same thickness but made of less plies. For example, 6.5mm plywood of 7 plies is more expensive than 6.5mm plywood of 5 plies. Because if No. of Plies is more, more glue will be used and the labor costs will rise accordingly .
If the plywoods’ thickness are the same , usually plywood of more plies are of premium quality .
