ISO 4018 Dimensions for Class C Hexagon Head Screws
| Dimension | a | d1 | d2 | s | shearing |
|---|---|---|---|---|---|
| 2 | 0.2 | 2.3 | 1.9 | 0.2 | 1.5 |
| 2.5 | 0.25 | 2.8 | 2.3 | 0.25 | 2.4 |
| 3 | 0.25 | 3.3 | 2.7 | 0.3 | 3.5 |
| 4 | 0.5 | 4.4 | 3.4 | 0.5 | 8th |
| 5 | 0.5 | 5.4 | 4.4 | 0.5 | 10.4 |
| 6 | 0.7 | 6.4 | 4.9 | 0.75 | 18 |
| 8 | 1.5 | 8.5 | 7 | 0.75 | 24 |
| 10 | 2 | 10.5 | 8.5 | 1 | 40 |
| 12 | 2 | 12.5 | 10.5 | 1 | 48 |
| 13 | 2 | 13.5 | 11 | 1.25 | 66 |
| 16 | 2 | 16.5 | 13.5 | 1.5 | 98 |
| 21 | 2 | 21.5 | 17.5 | 2 | 168 |