QUALITY DIRECTIVES
Page QUALITY DIRECTIVES-8
Z001007/0_4_September 2007
INSTALLATION INSTRUCTION
3.4. TIGHTENING TORQUES
The values in this table refer to industrial standards and are to be applied in case of no indication of specific
tightening torques.
For studs, the tightening torques are to be reduced for 50 %.
µ total *)
0,100
µ total
0,125
µ total
0,140
MA in Nm
MA in NM
MA in NM
8,8
10,9
12,9
8,8
10,9
12,9
8,8
10,9
2,9
nominal Ø
nominal Ø
nominal Ø
M 4
2,4
3,3
4
M 4
2,7
3,88
4,6
M 4
2,9
4,1
4,9
M 5
4,9
7
8
M 5
5,5
8
9,5
M 5
6
8,5
10
M 6
8
12
14
M 6
9,5
13
16
M 6
10
14
17
(M 7)
13
19
23
(M 7)
15
22
26
(M 7)
16
23
28
M 8
20
28
34
M 8
23
32
39
M 8
25
35
41
M 10
40
56
67
M 10
46
64
77
M 10
49
69
83
M 12
69
98
115
M 12
80
110
135
M 12
86
120
145
M 14
110
155
185
M 14
125
180
215
M 14
135
190
230
M 16
170
240
285
M 16
195
275
330
M 16
210
295
355
M 18
235
330
395
M 18
270
390
455
M 18
290
405
485
M 20
330
465
560
M 20
385
540
650
M 20
410
580
690
M 22
445
620
750
M 22
510
720
870
M 22
550
780
930
M 24
570
800
960
M 24
660
930
1100
M 24
710
1000
1200
M 27
840
1200
1400
M 27
980
1400
1650
M 27
1050
1500
1800
M 30
1150
1600
1950
M 30
1350
1850
2250
M 30
1450
2000
2400
nominal Ø
nominal Ø
nominal Ø
M 8x1
22
30
36
M 8x1
25
35
42
M 8x1
27
38
45
M 10x1,25
42
59
71
M 10 x 1,25
49
68
82
M 10x1,25
52
73
88
M 12x1,25
76
105
130
M 12x1,25
88
125
150
M 12x1,25
95
135
160
M 12x1,5
72
100
120
M 12x1,5
83
115
140
M 12x1,5
90
125
150
M 14x1,5
120
165
200
M 14x1,5
140
195
235
M 14x1,5
150
210
250
M 16x1,5
180
250
300
M 16x1,5
210
295
350
M 16x1,5
225
315
380
M 18x1,5
260
365
435
M 18x1,5
305
425
510
M 18x1,5
325
460
550
M 20x1,5
360
510
610
M 20x1,5
425
600
720
M 20x1,5
460
640
770
M 22x1,5
480
680
810
M 22x1,5
570
800
960
M 22x1,5
610
860
1050
M 24x2
610
860
1050
M 24x2
720
1000
1200
M 24x2
780
1100
1300
M 27x2
900
1250
1500
M 27x2
1050
1500
1800
M 27x2
1150
1600
1950
M 30x2
1250
1750
2100
M 30x2
1450
2050
2500
M 30x2
1600
2250
2700
If the tightening torque of a screw connection is not achieved, the strength of the screw / nut is insufficient or
the ratio of friction does not correspond. In any of these cases, the screw / nut is to be exchanged
*) µ total = total friction coefficient
grade of
strength
metric
control thread
metric
control thread
metric
control thread
metric
control thread
metric
control thread
grade of
strength
grade of
strength
metric
control thread