GB 8 – 1988 – Bu lông đầu vuông
Screw Thread | M10 | M12 | (M14) | M16 | (M18) | M20 | (M22) | M24 | (M27) | M30 | M36 | M42 | M48 | |
P | Pitch | 1.50 | 1.75 | 2.0 | 2.0 | 2.5 | 2.5 | 2.5 | 3 | 3 | 3.5 | 4 | 4.5 | 5 |
b | L≤125 | 26 | 30 | 34 | 38 | 42 | 46 | 50 | 54 | 60 | 66 | 78 | / | / |
125<L≤200 | 32 | 36 | 40 | 44 | 48 | 52 | 56 | 60 | 66 | 72 | 84 | 96 | 108 | |
200<L | / | / | 53 | 57 | 61 | 65 | 69 | 73 | 79 | 85 | 97 | 109 | 121 | |
e | min | 20.24 | 22.84 | 26.21 | 30.11 | 34.01 | 37.91 | 42.9 | 45.5 | 52.0 | 58.5 | 69.94 | 82.03 | 95.03 |
k | Nominal Size | 7 | 8 | 9 | 10 | 12 | 13 | 14 | 15 | 17 | 19 | 23 | 26 | 30 |
max | 7.45 | 8.45 | 9.45 | 10.75 | 12.90 | 13.90 | 14.90 | 15.90 | 17.90 | 20.05 | 24.05 | 27.05 | 31.05 | |
min | 6.55 | 7.55 | 8.55 | 9.25 | 11.10 | 12.10 | 13.10 | 14.10 | 16.10 | 17.95 | 21.95 | 24.95 | 28.95 | |
s | max | 16 | 18 | 21 | 24 | 27 | 30 | 34 | 36 | 41 | 46 | 55 | 65 | 75 |
min | 15.57 | 17.57 | 20.16 | 23.16 | 26.16 | 29.16 | 33 | 35 | 40 | 45 | 53.8 | 63.1 | 73.1 | |
x | max | 3.8 | 4.2 | 5 | 5 | 6.3 | 6.3 | 6.3 | 7.5 | 7.5 | 8.8 | 10 | 11.3 | 12.5 |
Weight of per 1000 steel products(≈kg) | – | – | – | – | – | – | – | – | – | – | – | – | – |