Chapter 8 General Reference
77
Thread Torque Chart (Metric)
FINE THREAD TORQUE CHART (METRIC)
COARSE THREAD TORQUE CHART (METRIC)
TIGHTENING TORQUE
TIGHTENING TORQUE
SIZE
(DIA-
TPI)
BOLT
DIA.
(INCHES)
SAE J429
GRADE 5
SAE J429
GRADE 8
SIZE
(DIA-
TPI)
BOLT DIA
(INCHES)
SAE J429
GRADE 5
SAE J429
GRADE 8
PLAIN
(KG-M)
PLATED
(KG-M)
PLAIN
(KG-M)
PLATED
(KG-M)
PLAIN
(KG-M)
PLATED
(KG-M)
PLAIN
(KG-M)
PLATED
(KG-M)
5/16-24 0.3125
3
2
4
3
5/16-18 0.3125
2
2
3
2
3/8-24
0.375
5
4
7
5
3/8-16
0.375
4
3
6
5
7/16-20 0.4375
8
6
11
8
7/16-14 0.4375
7
5
10
7
1/2-20
0.5
12
9
17
12
1/2-13
0.5
10
8
15
11
9/16-18 0.5625
17
12
24
18
9/16-12 0.5625
15
11
21
16
5/8-18
0.625
24
18
33
25
5/8-11
0.625
21
16
30
22
3/4-16
0.75
41
31
58
44
3/4-10
0.75
37
28
52
39
7/8-11
0.875
62
45
93
69
7/8-9
0.875
55
41
84
63
1-12
1
89
67
138
103
1-8
1
82
62
126
94
1 1/8-12 1.125
123
93
200
150
1 1/8-7
1.125
110
82
178
133
1 1/4-12 1.25
171
129
278
209
1 1/4-7
1.25
155
116
251
188
1 3/8-12 1.375
232
174
375
281
1 3/8-6
1.375
203
152
329
246
1 1/2-12 1.5
304
228
492
369
1 1/2-6
1.5
270
210
438
328
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 kilogram-meters.
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 disulphite, collodial 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
torqueing. Failure to replace gear-bearing
bolts may result in bolt failure due to metal
fatigue causing death or serious injury.
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