Overview
Overview of a selection of square hole perforations
| Hole width w (mm) | Pitch t (mm) | Ao (%) |
|---|---|---|
| 1.5 | 3 | 25 |
| 3 | 5-6 | 36-25 |
| 4 | 6-12 | 47.4-11 |
| 5 | 7.5-9 | 44.4-31 |
| 6 | 8-11 | 56.5-29.8 |
| 8 | 10-14 | 64-32.6 |
| 10 | 12-20 | 69.5-25 |
| 12 | 16-18 | 56.2-44.4 |
| 15 | 20-23 | 56.2-42.5 |
| 20 up to approx. 60 | 22.5-32 | 79-39 |