GB /T 1228 – 2006 – Bu lông kết cấu
Screw Thread | M12 | M16 | M20 | (M22) | M24 | (M27) | M30 | |
P | Pitch | 1.75 | 2 | 2.5 | 2.5 | 3 | 3 | 3.5 |
c | max | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
min | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | |
da | max | 15.23 | 19.23 | 24.32 | 26.32 | 28.32 | 32.84 | 35.84 |
ds | max | 12.43 | 16.43 | 20.52 | 22.52 | 24.52 | 27.84 | 30.84 |
min | 11.57 | 15.57 | 19.48 | 21.48 | 23.48 | 26.16 | 29.16 | |
dw | min | 19.2 | 24.9 | 31.4 | 33.3 | 38.0 | 42.8 | 46.5 |
e | min | 22.78 | 29.56 | 37.29 | 39.55 | 45.2 | 50.85 | 55.37 |
k | Nominal Size | 7.5 | 10 | 12.5 | 14 | 15 | 17 | 18.7 |
max | 7.95 | 10.75 | 13.4 | 14.9 | 15.9 | 17.9 | 19.75 | |
min | 7.05 | 9.25 | 11.6 | 13.1 | 14.1 | 16.1 | 17.65 | |
k1 | min | 4.9 | 6.5 | 8.1 | 9.2 | 9.9 | 11.3 | 12.4 |
r | min | 1.0 | 1.0 | 1.5 | 1.5 | 1.5 | 2.0 | 2.0 |
s | max | 21 | 27 | 34 | 36 | 41 | 46 | 50 |
min | 20.16 | 26.16 | 33 | 35 | 40 | 45 | 49 | |
Weight of per 1000 steel products(≈kg) | – | – | – | – | – | – | – | |
Length of Thread b | – | – | – | – | – | – | – |