DIN 558 – 1987 – Bu lông lục giác
| Screw Thread | M5 | M6 | M8 | M10 | M12 | M16 | M20 | M24 | M30 | M36 | |
| d | |||||||||||
| P | Pitch | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3 | 3.5 | 4 |
| a | max | 3.2 | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 14 | 16 |
| c | max | 0.5 | 0.5 | 0.6 | 0.6 | 0.6 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
| da | max | 6 | 7.2 | 10.2 | 12.2 | 14.7 | 18.7 | 24.4 | 28.4 | 35.4 | 42.4 |
| dw | min | 6.7 | 8.7 | 11.4 | 15.4 | 17.2 | 22 | 27.7 | 33.2 | 42.7 | 51.1 |
| e | min | 8.63 | 10.89 | 14.2 | 18.72 | 20.88 | 26.17 | 32.95 | 39.55 | 50.85 | 60.79 |
| k | Nominal Size | 3.5 | 4 | 5.3 | 6.4 | 7.5 | 10 | 12.5 | 15 | 18.7 | 22.5 |
| min | 3.12 | 3.62 | 4.92 | 5.95 | 7.05 | 9.25 | 11.6 | 14.1 | 17.65 | 21.45 | |
| max | 3.88 | 4.38 | 5.68 | 6.85 | 7.95 | 10.75 | 13.4 | 15.9 | 19.75 | 23.55 | |
| k1 | min | 2.2 | 2.5 | 3.45 | 4.2 | 4.95 | 6.5 | 8.1 | 9.9 | 12.4 | 15 |
| r | min | 0.2 | 0.25 | 0.4 | 0.4 | 0.6 | 0.6 | 0.8 | 0.8 | 1 | 1 |
| s | max=nominal size | 8 | 10 | 13 | 17 | 19 | 24 | 30 | 36 | 46 | 55 |
| min | 7.64 | 9.64 | 12.57 | 16.57 | 18.48 | 23.16 | 29.16 | 35 | 45 | 53.8 | |
| Weight of per 1000 steel products(≈kg) | – | – | – | – | – | – | – | – | – | – | |
