BS 4320 / DIN 125-1: Basic dimensions Form A washers for selected sizes
| Nominal size | Inside diameter (d1) | Outside diameter (d2) | Thickness (s) | ||||||
| min. | BS 4320 max. | DIN 125-1 max. | BS4320 min. | BS 4320 max. | DIN 125-1 min. | DIN 125-1 max. | min. | max. | |
| M5 | 5.3 | 5.5 | 5.48 | 9.7 | 10 | 9.64 | 10 | 0.9 | 1.1 |
| M6 | 6.4 | 6.7 | 6.62 | 12.1 | 12.5 | 11.57 | 12 | 1.4 | 1.8 |
| M8 | 8.4 | 8.7 | 8.62 | 16.6 | 17 | 15.57 | 16 | 1.4 | 1.8 |
| M10 | 10.5 | 10.9 | 10.77 | 20.5 | 21 | 19.48 | 20 | 1.8 | 2.2 |
| M12 | 13.0 | 13.4 | 13.27 | 23.5 | 24 | 23.48 | 24 | 2.3 | 2.7 |
| M16 | 17.0 | 17.4 | 17.27 | 29.5 | 30 | 29.48 | 30 | 2.7 | 3.3 |
| M20 | 21 | 21.5 | 21.33 | 36.2 | 37 | 36.38 | 37 | 2.7 | 3.3 |
| M24 | 25 | 25.5 | 25.33 | 43.2 | 44 | 43.38 | 44 | 3.7 | 4.3 |