Torque Tensioning

Table 1 - Torque-Tension Relationships for SAE Grades 2, 5 and 8
Nom.
Size
and
Threads
/ in.

Stress
Area
(1)
in. 2
Grade
2
Clamp
Load
Lb.
Grade
2
Torque
Dry
k=0.2
in - lb.
Grade 2
Clamp
Load lb.
Grade
5
Clamp
Load
lb.
Grade
5
Torque
Dry k=0.2
in-lb.
Grade 5
Torque
Lub
k=0.15
in-lb
Grade
8
Clamp
Load
Lb.
Grade
8
Torque
Dry
k=0.2
in-lb.
Grade
8
Torque
Lub
k=0.15
in-lb.
0.138-40
0.01014
418.0
10.2
7.7
647.5
15.6
11.7
913.5
23.4
17.6
0.138-32
0.00909
401.0
9.6
7.2
579.5
14.4
10.8
818.0
21.0
15.8
0.164.36
0.01473
608.0
17.4
13.1
938.5
27.6
20.7
1306.0
40.2
30.2
0.164-31
0.01401
578.0
16.8
12.6
893.0
25.8
19.4
1261.0
40.2
30.2
0.190-32
0.01999
825.0
28.2
21.2
1275.0
43.2
32.4
1798.5
63.6
47.7
0.190-24
0.01753
723.0
24.6
18.5
1117.5
37.2
27.9
1577.5
55.8
41.9
0.250-28
0.03637
1500.0
75.0
56.0
2319.0
116.0
87.0
3273.0
164.0
123.0
0.250-20
0.03182
1313.0
66.0
49.0
2029.0
101.0
76.0
2864.0
143.0
107.0
0.3125-24
0.05807
2395.0
150.0
112.0
3700.0
230.0
173.0
5225.0
327.0
245.0
0.3125-18
0.05243
2163.0
135.0
101.0
3342.0
209.0
157.0
4719.0
295.0
221.0
.0375-24
0.08783
3623.0
272.0
204.0
5600.0
420.0
315.0
7905.0
893.0
445.0
.0375-16
0.07749
3196.0
240.0
180.0
4940.0
370.0
278.0
6974.0
523.0
392.0
0.4375-20
0.11872
4896.0
428.0
321.0
7567.0
662.0
496.0
10638.0
935.0
700.0
0.4375-14
0.10631
4385.0
384.0
288.0
6777.0
593.0
445.0
9567.0
837.0
628.0
0.500-20
0.15995
6598.0
660.0
495.0
10197.0
1020.0
764.0
14396.0
1440.0
1080.0
0.500-13
0.14190
5853.0
585.0
439.0
9046.0
904.0
678.0
12771.0
1277.0
958.0
Table 2 - Torque-Tension Relationships for Metric Property Classes
Major
Diameter
and
Thread
Pitch

Stress Area

mm2

Class
4.6
Clamp Load

kN

Class 4.6
Torque
Dry
k=0.2
N-m

Class 4.6
Torque
Lub
k=0.15
N-m

Class
4.8
Clamp Load

kN

Class 4.8
Torque
Dry
k=0.2
N-m

Class 4.8
Torque
Lub
k=0.15
N-m

Class 5.8
Clamp Load

kN

Class 5.8
Torque
Dry
k=0.2
N-m

Class 5.8
Torque
Lub
k=0.15
N-m
3.0x0.5
5.03
.085
0.50
0.40
1.17
0.70
0.50
.
.
.
3.5x0.6
6.78
1.14
0.80
0.60
1.58
1.10
0.80
.
.
.
4.0x0.7
8.78
1.14
1.20
0.90
2.04
1.60
1.20
.
.
.
5.0x0.8
14.2
2.40
2.40
1.80
3.30
3.30
2.50
4.05
4.00
3.00
6.0x1.0
20.10
3.40
4.00
3.00
4.67
5.66
4.20
5.73
6.90
5.20
8.0x1.25
36.60
6.18
9.90
7.40
8.51
13.60
10.20
10.40
16.70
12.50
10.0x1.50
58.00
9.79
19.60
14.70
13.48
27.00
20.00
16.50
33.10
24.80
12.0x1.75
84.30
14.22
34.10
25.60
19.60
47.00
35.00
24.00
58.00
43.00
Tensile Strength
Proof Load Stress		 400 MPa
224 MPa		 420 MPa
310 MPa		 520 MPa
380 MPa
Major
Diameter
and
Thread
Pitch

Stress Area

mm2

Class
8.8
Clamp Load

kN

Class 8.8
Torque
Dry
k=0.2
N-m

Class 8.8
Torque
Lub
k=0.15
N-m

Class
9.8
Clamp Load

kN

Class 9.8
Torque
Dry
k=0.2
N-m

Class 9.8
Torque
Lub
k=0.15
N-m

Class 10.9
Clamp Load

kN

Class 10.9
Torque
Dry
k=0.2
N-m

Class 10.9
Torque
Lub
k=0.15
N-m
3.0x0.5
5.03
.
.
.
.
.
.
.
.
.
3.5x0.6
6.78
.
.
.
.
.
.
.
.
.
4.0x0.7
8.78
.
.
.
.
.
.
.
.
.
5.0x0.8
14.20
.
.
.
.
.
.
.
.
.
6.0x1.0
20.10
.
.
.
.
.
.
.
.
.
8.0x1.25
36.60
16.50
26.40
19.80
17.80
28.50
21.40
22.80
36.50
27.30
10.0x1.50
58.00
26.10
52.20
39.20
28.30
56.60
42.40
36.10
72.20
54.20
12.0x1.75
84.30
37.90
91.00
68.00
41.10
99.00
74.00
52.50
126.00
94.00
Tensile Strength
Proof Load Stress		 830 MPa
600 MPa		 900 Pa
650 Pa		 1040 Pa
830 Pa

NOTE: The stress area of threaded series not included in Table 2 may be computed from the equation: As=0.7854 (D - 0.9382P)2 WHERE: As=Stress area in mm2 D=Diameter in mm P=Pitch in mm

CAUTION: The previously listed torque and resulting tension are provided as an advisory guide. Individual application discretion is recommended. The content, has been presented as accurately as possible, but responsibility for its application lies with the user, and Elgin Fastener Group is not responsible for any loss, claim, or damage arising there from. A complete discussion and tutorial on Torque Tensioning is available from Elgin Fastener Group by request.

Torque Tensioning
Screw Point Types
Pilot Hole Sizes
Bolt & Screw Head Types
Weights per Thousand
Unified External Screw Threads
Rod & Bolt Diameters
Metric Conversions
Hole Sizes for Die Casting
Material Strength
Drive Tool Sizes
Hardness Conversions

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