TM 5-3895-346-14
ENGINE OVERHAUL
SPECIFICATIONS
STANDARD BOLT AND NUT TORQUE SPECIFICATIONS
260M BOLTS
280M OR BETTER
THREAD
THREAD
SIZE
(lb ft)
(Nm)
SIZE
(lb ft)
(Nm)
1/4-20
5-7
7-9
1/4-20
7-9
10-12
1/4-28
6-8
8-11
1/4-28
810
11-14
5/16-18
10-13
14-18
5/16-18
13-17
18-23
5/16-24
11-14
15-19
5/16-24
15-19
20-26
3/8-16
23-26
31-35
3/8-16
30-35
41-47
3/8-24
26-29
35-40
3/8-24
35-39
47-53
7/16-14
35-38
47-51
7/16-14
46-50
62-68
7/16-20
43-46
58-62
7/16-20
57-61
77-83
1/2-13
53-56
72-76
1/2-13
71-75
96-102
1/2-20
62-70
84-95
1/2-20
83-93
113-126
9/16-12
68-75
92-102
9/16-12
90-100
122-136
9/16-18
80-88
109-119
9/16-18
107-117
146-159
5/8-11
103-110
140-149
5/8-11
137-147
186-200
5/8-18
126-134
171-181
5/8-18
168-178
228-242
3/4-10
180-188
244-254
3/4-10
240-250
325-339
3/4-16
218-225
295-305
3/4-16
290-300
393-407
7/8-9
308-315
417-427
7/8-9
410-420
556-569
7/8-14
356-364
483-494
7/8-14
475-485
644-657
1-8
435-443
590-600
1-8
580-590
786-800
1-14
514-521
697-705
1-14
685-695
928-942
Grade identification markings are normally stamped on the heads of the bolts. To aid identification of the
various bolts used in Detroit Diesel engines, refer to the following chart.
BOLT IDENTICATION CHART
Grade Identification
GM
SAE Grade
Nominal Size
Tensile
Marking on Bolt Head
Number
Designatio
Diameter
Strength Min.
n
(inch)
(psi)
None
GM 255-M
1
No. 6 thru 1 1/2
60,000
None
GM 260-M
2
No. 6 thru 3/4
74,000
over 3/4 to 1 1/2
60,000
Bolts and Screws
GM 280-M
5
No. 6 thru 1
120,000
over 1 to 1 1/2
105,000
Hex Head Sems Only
GM 275-M
5.1
No. 6 thru 3/8
120,000
Bolts and Screws
BM 290-M
7
1/4 thru 1 1/2
133,000
Bolts and Screws
GM 300-M
8
1/4 thru 1 1/2
150,000
Bolts and Screws
GM 455-M
None
No. 6 thru 1 1/2
55,000
386
