EN 1665 (R) – 1997 – Bu lông lòng đen
| Screw Thread | M5 | M6 | M8 | M10 | M12 | (M14) | M16 | M20 | |
| P | Pitch | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2 | 2.5 |
| b | L≤125 | 16 | 18 | 22 | 26 | 30 | 34 | 38 | 46 |
| 125＜L≤200 | / | / | 28 | 32 | 36 | 40 | 44 | 52 | |
| L＞200 | – | – | – | – | – | – | 57 | 65 | |
| dc | max | 11.8 | 14.2 | 18 | 22.3 | 26.6 | 30.5 | 35 | 43 |
| ds | max | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 20 |
| min | 4.82 | 5.82 | 7.78 | 9.78 | 11.73 | 13.73 | 15.73 | 19.67 | |
| k | max | 5.8 | 6.6 | 8.1 | 10.4 | 11.8 | 13.7 | 15.4 | 18.9 |
| s | max | 8 | 10 | 13 | 16 | 18 | 21 | 24 | 30 |
| min | 7.78 | 9.78 | 12.73 | 15.73 | 17.73 | 20.67 | 23.67 | 29.67 | |
| c | min | 1 | 1.1 | 1.2 | 1.5 | 1.8 | 2.1 | 2.4 | 3 |
| e | min | 8.71 | 10.95 | 14.26 | 17.62 | 19.86 | 23.15 | 26.51 | 33.23 |
| Length of Thread b | – | – | – | – | – | – | – | – | |
