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OM1200 02/11
STANDARD TIGHTENING TORQUES
For SAE Grade 5 and Grade 8 Cap screws
The following specifications apply to required assem-
bly torques for all grade 5 and grade 8 cap screws.
• Cap screw threads and seats shall be lubricated
when assembled.
Unless
instructions
otherwise, these standard torque values are to be
used with simple lithium base chassis grease
(multi-purpose EP NLGI) or a rust- preventive
grease (see list, previous page) on the threads.
• Torques are calculated to give a clamping force
of approximately 75% of proof load.
Torque -
Cap
Grade 5
Screw
Size
N·m
ft lb
1/4-20
9.5
7
1/4-28
10.8
8
5/16-18
20.3
15
5/16-24
22
16
3/8-16
34
25
3/8-24
41
30
7/16-14
54
40
7/16-20
61
45
1/2-13
88
65
1/2-20
95
70
9/16-12
122
90
9/16-18
129
95
5/8-11
169
125
5/8-18
183
135
3/4-10
298
220
specifically
recommend
Standard Tightening Torque
for SAE Hex Head Cap Screw And Nut Assembly
Torque -
Grade 8
kg·m
N·m
ft lb
kg·m
0.97
13.6
10
1.38
1.11
14.9
11
1.52
2.07
28
21
2.90
2.21
30
22
3.04
3.46
47
35
4.84
4.15
54
40
5.5
5.5
79
58
8.0
6.2
84
62
8.57
9
122
90
12.4
9.7
129
95
13.1
12.4
169
125
17.3
13.1
183
135
18.7
17.3
237
175
24.2
18.7
258
190
26.2
30.4
420
310
42.8
1 ft. lb. = 0.138 kg·m = 1.356 N.m
Torque Tables And Conversion Charts - Section 12
• The maximum torque tolerance shall be ±10% of
the torque value shown.
• In the following table under Cap Screw Size, the
first number represents the shank diameter (in.).
The second number represents threads per inch.
Example: 7/16 - 20
7/16 = shank diameter (7/16 inch (0.438 inch))
20 = threads per inch
TABLE 2.
Torque -
Cap
Grade 5
Screw
Size
N·m
ft lb
3/4-16
319
235
7/8-9
475
350
7/8-14
508
375
1.0-8
712
525
1.0-12
759
560
1.0-14
773
570
1 1/8-7
881
650
1 1/8-12
949
700
1 1/4-7
1234
910
1 1/4-12
1322
975
1 3/8-6
1627
1200
1 3/8-12
1776
1310
1 1/2-6
2142
1580
1 1/2-12
2305
1700
Page 12-3
Torque -
Grade 8
kg·m
N·m
ft lb
kg·m
32.5
454
335
46.3
48.4
678
500
69.2
51.9
719
530
73.3
72.6
1017
750
103.7
77.4
1071
790
109.3
78.8
1085
800
110.6
89.9
1424
1050
145
96.8
1546
1140
158
125.9
2007
1480
205
134.8
2142
1580
219
166
2630
1940
268
181
2874
2120
293
219
3471
2560
354
235
3756
2770
383
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