Recommended minimum Torque Values are in N-m.
Torque values are applicable for Bolt Materials - ASTM A193 B7, B16 & ASTM A320 L7.
BOLT TORQUING
| Flange NPS |
No of Bolts |
Bolt size |
Bolt Stress (MPa) |
Torque N-m μ=0.09 Copperslip |
Torque N-m μ=0.14 Chesterton Nickel |
Torque N-m μ=0.225 Unlubricated |
|---|---|---|---|---|---|---|
| ½'' | 4 | ¾ | 345 | 173 | 254 | 392 |
| ¾'' | 4 | ¾ | 345 | 173 | 254 | 392 |
| 1'' | 4 | ⅞ | 379 | 304 | 447 | 691 |
| 1¼'' | 4 | 1 | 379 | 453 | 666 | 1029 |
| 1½'' | 4 | 1 ⅛ | 379 | 659 | 974 | 1510 |
| 2'' | 8 | 1 | 379 | 453 | 666 | 1029 |
| 2½'' | 8 | 1 ⅛ | 379 | 659 | 974 | 1510 |
| 3'' | 8 | 1 ¼ | 345 | 835 | 1240 | 1929 |
| 4'' | 8 | 1 ½ | 379 | 1625 | 2430 | 3798 |
| 5'' | 8 | 1 ¾ | 379 | 2618 | 3935 | 6174 |
| 6'' | 8 | 2 | 379 | 3958 | 5973 | 9399 |
| 8'' | 12 | 2 | 379 | 3958 | 5973 | 9399 |
| 10'' | 12 | 2 ½ | 345 | 7122 | 10809 | 17077 |
| 12'' | 12 | 2 ¾ | 379 | 10502 | 15972 | 25272 |