Parts 33
Thread Torque Charts
FINE THREAD BOLTS (ENGLISH)
COARSE THREAD BOLTS (ENGLISH)
SIZE BOLT
DIA.
GRADE 5
SAE J429
GRADE 5
GRADE 8
SAE J429
GRADE 8
SIZE BOLT
DIA.
GRADE 5
SAE J429
GRADE 5
GRADE 8
SAE J429
GRADE 8
(DIA-TPI) (INCHES) PLAIN
PLATED PLAIN PLATED (DIA-
TPI)
(INCHES) PLAIN PLATED
PLAIN
PLATED
(FT-LB) (FT-LB) (FT-LB) (FT-LB) (FT-LB)
(FT-LB)
(FT-LB)
(FT-LB)
5/16-24
0.3125
19 14 27 20
5/16-18 0.3125 17
13
25
18
3/8-24
0.375
35 26 49 35
3/8-16 0.375 31
23
44
33
7/16-20
0.4375
55 41 78 58
7/16-14 0.4375 49
37
70
52
1/2-20
0.5 90 64 120
90
1/2-13 0.5
75
57
105
80
9/16-18
0.5625
120 90 170 130
9/16-12 0.5625 110
82
155
115
5/8-18
0.625 170 130 240 180
5/8-11 0.625 150
115
220
160
3/4-16
0.75 300 225 420 315
3/4-10 0.75
265
200
375
280
7/8-11
0.875 445 325 670 500
7/8-9 0.875 395 295
605
455
1-12 1
645 485 995 745
1-8 1
590 445 910
680
1
1/8-12
1.125 890 670 1445
1085
1
1/8-7 1.125
795
595
1290
965
1
1/4-12
1.25 1240 930 2010 1510
1 1/4-7
1.25
1120
840
1815
1360
1
3/8-12
1.375 1675 1255 2710 2035
1 3/8-6
1.375
1470
1100
2380
1780
1
1/2-12
1.5
2195 1645 3560 2670
1 1/2-6
1.5
1950
1460
3160
2370
NOTES
1
Tightening torques provided are midrange.
2
Consult bolt manufacturer’s particular specifications, when provided.
3
Use flat washers of equal strength.
4
All torque measurements are given in foot-pounds.
5
Torque values specified are for bolts with residual oils or no special lubricants applied. If special lubricants of
high stress ability, such as Never-Seez compound graphite and oil, molybdenum disulphide, colloidal copper or
white lead are applied, multiply the torque values in the charts by the factor .90. The use of Loctite does not affect
the torque values listed above.
WARNING
Anytime a gear-bearing bolt is removed, it must be replaced with a new bolt of the identical
grade and size. Once a bolt has been torqued to 75% of its proof load and then removed, the
torque coefficient may no longer be the same as when the bolt was new thus giving
indeterminate clamp loads after torquing. Failure to replace gear-bearing bolts may result in bolt
failure due to metal fatigue causing death or serious injury.
