The following table lists the preload forces and tightening torques for bolt connections, strength
classes 8.8; 10.9; 12.9:
Table 5-2 Preload forces and tightening torques
Nominal
thread di‐
ameter
Bolt
strength
class
Preload force for bolt connection
classes from the table in chapter
Bolt connection classes (Page 74).
Tightening torque for bolt connection
classes from the table in chapter Bolt
connection classes (Page 74)
d
mm
C D E C D E
F
M min.
N
M
A
Nm
M10 8.8 18 000 11 500 7 200 44.6 38.4 34.3
10.9 26 400 16 900 10 600 65.4 56.4 50.4
12.9 30 900 19 800 12 400 76.5 66.0 58.9
M12 8.8 26 300 16 800 10 500 76.7 66.1 59.0
10.9 38 600 24 700 15 400 113 97.1 86.6
12.9 45 100 28 900 18 100 132 114 101
M16 8.8 49 300 31 600 19 800 186 160 143
10.9 72 500 46 400 29 000 273 235 210
12.9 85 000 54 400 34 000 320 276 246
M20 8.8 77 000 49 200 30 800 364 313 280
10.9 110 000 70 400 44 000 520 450 400
12.9 129 000 82 400 51 500 609 525 468
M24 8.8 109 000 69 600 43 500 614 530 470
10.9 155 000 99 200 62 000 875 755 675
12.9 181 000 116 000 72 500 1 020 880 790
M30 8.8 170 000 109 000 68 000 1 210 1 040 930
10.9 243 000 155 000 97 000 1 720 1 480 1 330
12.9 284 000 182 000 114 000 2 010 1 740 1 550
M36 8.8 246 000 157 000 98 300 2 080 1 790 1 600
10.9 350 000 224 000 140 000 2 960 2 550 2 280
12.9 409 000 262 000 164 000 3 460 2 980 2 670
M42 8.8 331 000 212 000 132 000 3 260 2 810 2 510
10.9 471 000 301 000 188 000 4 640 4 000 3 750
12.9 551 000 352 000 220 000 5 430 4 680 4 180
M48 8.8 421 000 269 000 168 000 4 750 4 090 3 650
10.9 599 000 383 000 240 000 6 760 5 820 5 200
12.9 700 000 448 000 280 000 7 900 6 810 6 080
M56 8.8 568 000 363 000 227 000 7 430 6 400 5 710
10.9 806 000 516 000 323 000 10 500 9 090 8 120
12.9 944 000 604 000 378 000 12 300 10 600 9 500
M64 8.8 744 000 476 000 298 000 11 000 9 480 8 460
10.9 1 060 000 676 000 423 000 15 600 13 500 12 000
12.9 1 240 000 792 000 495 000 18 300 15 800 14 100
Assembly
5.6 Tightening procedure
Gear unit 5118en
Operating Instructions 10/2017 75