TM 5-3895-359-14&P
SPECIFICATIONS
STANDARD BOLT AND NUT TORQUE SPECIFICATIONS
260M BOLTS
280M OR BETTER
THREAD
THREAD
SIZE
(lb-ft)
Nm
SIZE
(lb-ft)
Nm
1/4-205-7 .....................................7-91/4-20 7-910-12
1/4-286-8 ....................................8-111/4-28 8-1011-14
5/16-1810-13 .............................. 14-185/16-1813-17
18-23
5/16-2411-14 .............................. 15-195/16-2415-19
20-26
3/8-1623-26 ............................... 31-353/8-1630-3541-47
3/8-2426-29 ............................... 35-403/8-2435-3947-53
7/16-1435-38 .............................. 47-517/16-1446-50
62-68
7/16-2043-46 .............................. 58-627/16-2057-61
77-83
1/2-1353-56 ............................... 72-761/2-1371-7596-102
1/2-2062-70 ............................... 84-951/2-2083-93113-126
9/16-1268-75 ............................. 92-1029/16-1290-100
122-136
9/16-1880-88 ............................ 109-119
9/16-18107-117
146-159
5/8-11103-110 ......................... 140-1495/8-11137-147
186-200
5/8-18126-134 ......................... 171-1815/8-18168-178
228-242
3/4-10180-188 ......................... 244-2543/4-10240-250
325-339
3/4-16218-225 ......................... 295-3053/4-16290-300
393-407
7/8-9308-315 .......................... 417-4277/8-9410-420
556-569
7/8-14356-364 ......................... 483-4947/8-14475-485
644-657
1-8435-443............................ 590-6001-8 580-590
786-800
1-14514-521........................... 697-7051-14685-695
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.
Nominal Size
Grade Identification
GM
SAE Grade
Diameter
Tensile Strength
Marking on Bolt Head
Number
Designation
(inch)
Min. (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
GM 290-M
7
1/4 thru 1 1/2
133,000
Bolts and Screws
GM 300-M
8
1/4 thru I 1/2
150,000
Bolts and Screws
GM 455-M
None
No. 6 thru 1 1/2
55,000
12252
BOLT IDENTIFICATION CHART
10-8-24
