Installation and Operation Manual
E2K-405-0218 Rev. 2
February 2018
89
Appendix
Appendix
A.7
Common Bolt Tightening Torques
Grade 1
Grade 2
Grades 5, 5.2 & 5.1
Grades 8, 8.1 & 8.2
Thread Size &
Pitch
Clamp Load (lb)
Tightening
Torque (ft-lb)
Clamp Load (lb)
Tightening
Torque (ft-lb)
Clamp Load (lb)
Tightening
Torque (ft-lb)
Clamp Load (lb)
Tightening
Torque (ft-lb)
6 - 32
225
0.52
375
0.86
579
1.33
818
1.88
8 - 32
347
0.95
578
1.58
893
2.44
1260
3.44
10 - 24
433
1.37
722
2.29
1116
3.53
1575
4.99
12 - 24
599
2.16
998
3.59
1543
5.55
2178
7.84
1/4 - 20
787
3.28
1312
5.47
2027
8.45
2862
11.9
5/16 -18
1297
6.75
2162
11.3
3341
17.4
4716
24.6
3/8 - 16
1918
12.0
3197
20.0
4941
30.9
6975
43.6
7/16 - 14
2631
19.2
4385
32.0
6777
49.4
9567
69.8
1/2 - 1 3
3512
29.3
5853
48.8
9046
75.4
12771
106
9/16 - 12
4505
42.2
7508
70.4
11603
109
16380
154
5/8 - 11
5594
58.3
9323
97.1
14408
150
20340
212
3/4 - 10
8267
103
8267
103
21293
266
30060
376
7/8 - 9
11435
167
11435
167
29453
430
41580
606
1- 8
14999
250
14999
250
33633
561
54540
909
1-1/8 - 7
18884
354
18884
354
42347
794
68670
1288
1-1/4 - 7
23983
500
23983
500
53780
1120
87210
1817
1-3/8 - 6
28586
655
28586
655
64103
1469
103950
2382
1-1/2 - 6
34774
869
34774
869
77978
1949
126450
3161
English Units:
(Coarse Thread Series)
Tightening Torque = K * D * P
K = 0.2 (dry, unlubricated)
Clamp Load (P) = 75% of the Proof Load
D = Nominal Thread Size
The values presented in these tables are representative and have been compiled for the user’s benefit. Results can be influenced by
any number of variables including 1) excessive lubrication, 2) excessive design clamp load, 3) nicked or binding threads, 4) non-parallel
mating surfaces, and 5) inadequate torque control, to name a few. Therefore, Load expressly disclaims liability of any kind associated with
the application of the data shown herein.
Class 4.6
Class 5.8
Class 9.8
Class 10.9
Thread Size &
Pitch
Clamp Load (KN)
Tightening
Torque (N*m)
Clamp Load (KN)
Tightening
Torque (N*m)
Clamp Load (KN)
Tightening
Torque (N*m)
Clamp Load (KN)
Tightening
Torque (N*m)
M6 X 1
3.41
4.09
5.73
6.87
9.80
11.76
12.5
15
M7 X 1
4.90
6.86
8.24
11.5
14.1
19.72
18.0
25
M8 X 1.25
6.20
9.93
10.4
16.7
17.8
28.55
22.8
36
M10 X 1.5
9.8
19.7
16.5
33.1
28.3
56.55
36.1
72
M12 X 1.75
14.3
34.3
24.0
57.7
41.1
98.63
52.5
126
M14 X 2
19.5
54.6
32.8
91.8
56.1
157
71.6
200
M16 X 2
26.6
85.2
44.7
143
76.5
245
97.7
313
M18 X 2.5
32.5
117
54.7
197
93.6
337
120
430
M20 X 2.5
41.5
166
69.8
279
119
478
153
610
M22 X 2.5
51.4
226
86.4
380
148
650
189
830
M24 X 3
59.8
287
101
483
172
826
220
1055
M27 X 3
77.8
420
131
706
224
1208
286
1543
M30 X 3.5
95.1
571
160
959
273
1641
349
2095
M33 X 3.5
118
776
198
1305
338
2233
432
2851
M36 X 4
138
997
233
1676
398
2868
509
3662
M39 X 4
165
1290
278
2170
476
3711
608
4739
Metric Units:
(Coarse Thread Series)
Tightening Torque = K * D * P
K = 0.2 (dry, unlubricated)
Clamp Load (P) = 75% of the Proof Load
D = Nominal Thread Size