Basic size
Strength class
Material
70
80
M
A
(Nm)
M
A
(Nm)
M20
254
326
A2 / A4
M
A
= tightening torques
Tightening torque for self-locking hex nuts
Thread
M
A
(Nm)
Lubricant
M6
7,5 +1
–
M8
17 +2
–
M10
35 +4
–
M12
59 +6
–
M14
100 +10
–
M16
140 +14
–
M20
290 +29
–
M
A
= tightening torques
Tightening torques for stress bolt connections to MTN 5007 standard
This standard applies to stress pin bolts and stress bolts which are subjected to static and dynamic
load of strength class 10.9 as well as to the associated nuts.
Shank and junction dimensions to MMN 209 standard and material and manufacture to MMN 389
standard (bare metal or phosphatized).
The values in the table are based on a friction coefficient µtot = 0.125.
Threads and mating faces of screws and nuts must be coated with engine oil prior to assembly.
An assembly tolerance of +10% of the figures in the table is permitted due to unavoidable deviations
during the tightening process.
The figures in the table are for hand-tightening using a torque wrench.
Thread
Not torsion-protected M
A
(Nm)
Torsion-protected M
A
(Nm)
M6
9
12
M8
21
28
M8 x 1
24
30
M10
42
55
M10 x 1.25
46
60
M12
75
93
M12 x 1.5
78
99
M14
120
150
M14 x 1.5
135
160
M16
180
225
M16 x 1.5
200
245
M18
250
315
M18 x 1.5
300
360
M20
350
450
20 | General Information | M015655/05E 2015-06
TIM-ID: 0000002333 - 017
