Recommended minimum Torque Values are in N-m.
Torque values are applicable for Bolt Materials - ASTM A193 B7, B16 & ASTM A320 L7.

Bolt Torquing

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 ½ 276 40 59 90
¾'' 4 276 79 116 178
1'' 4 276 79 116 178
1¼'' 4 310 89 130 200
1½'' 4 ¾ 276 139 203 313
2'' 8 310 89 130 200
2½'' 8 ¾ 276 139 203 313
3'' 8 ¾ 310 156 229 352
4'' 8 310 249 366 565
5'' 8 1 310 371 545 842
6'' 12 1 310 371 545 842
8'' 12 1 ⅛ 310 539 797 1235
10'' 16 1 ¼ 310 752 1116 1736
12'' 20 1 ¼ 310 752 1116 1736
14'' 20 1 ⅜ 310 1014 1511 2356
16'' 20 1 ½ 310 1329 1988 3108
18'' 20 1 ⅝ 310 1704 2555 4002
20'' 24 1 ⅝ 310 1704 2555 4002
24'' 24 1 ⅞ 310 2656 4000 6286