Table 6.4 SAE Grade 8 Bolt and Grade 8 Free
Spinning Nut
Torque (ft·lbf)
(*in·lbf)
Torque (N·m)
Nominal
Size (A)
Min.
Max.
Min.
Max.
1/4-20
*150
*165
16.8
18.6
5/16-18
26
28
35
38
3/8-16
46
50
61
68
7/16-14
73
81
98
109
1/2-13
111
123
150
166
9/16-12
160
177
217
239
5/8-11
221
345
299
330
3/4-10
393
435
531
587
7/8-9
633
700
855
945
1-8
863
954
1165
1288
Figure 6.4: Bolt Grades
A - Nominal Size
B - SAE-8
C - SAE-5
D - SAE-2
6.1.2
Metric Bolt Specifications
Table 6.5 Metric Class 8.8 Bolts and Class 9 Free
Spinning Nut
Torque (ft·lbf)
(*in·lbf)
Torque (N·m)
Nominal
Size (A)
Min.
Max.
Min.
Max.
3-0.5
*13
*14
1.4
1.6
3.5-0.6
*20
*22
2.2
2.5
4-0.7
*29
*32
3.3
3.7
5-0.8
*59
*66
6.7
7.4
6-1.0
*101
*112
11.4
12.6
8-1.25
20
23
28
30
10-1.5
40
45
55
60
12-1.75
70
78
95
105
14-2.0
113
124
152
168
16-2.0
175
193
236
261
20-2.5
341
377
460
509
24-3.0
589
651
796
879
Figure 6.5: Bolt Grades
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159
Revision A