Screw­connection Classes, Tightening Torques And Initial­tensioning Forces; Screw­connection Classes; Tightening Torques And Initial­tensioning Forces - Siemens Flender H2NV Series Assembly And Operating Instructions Manual

6.9 Screw­connection classes, tightening torques and initial­tensioning forces
6.9.1 Screw­connection classes
The specified screw connections are to be fastened applying the tightening torques specified in the table
below.
Table 7: Screw­connection classes
Screw-
connection
class
C
D
E
Foundation bolts, hub bolts and bearing­cover bolts must always be tightened in
accordance with screw­connection class "C"!
6.9.2 Tightening torques and initial­tensioning forces
The tightening torques apply to friction coefficients of μ
The friction coefficient μ
phosphatised and dry, cut mating threads in steel or cast iron. Lubricants which alter the friction
coefficient must not be used and may overload the screw connection.
Table 8: Initial­tensioning forces and tightening torques for screw connections of strength classes
8.8; 10.9; 12.9 with a common friction coefficient of μ
Nominal Strength
thread
diameter of the bolt
d
mm
M10
M12
M16
M20
M24
Distribution of
emitted torque on
the tool
± 5 % up to ± 10 %
± 10 % up to ± 20 %
± 20 % up to ± 50 %
= 0.14 applies here to lightly oiled steel bolts, black­annealed or
total
Initial-tensioning force
class for screw-connection classes
from table 7
C
8.8 18000
10.9 26400
12.9 30900
8.8 26300
10.9 38600
12.9 45100
8.8 49300
10.9 72500
12.9 85000
8.8 77000
10.9 110000
12.9 129000
8.8 109000
10.9 155000
12.9 181000
BA 5060 EN 04/2011
Tightening procedure
(Usually the tightening processes lie within
the stated tool distributions)
‐ Hydraulic tightening with mechanical screwdriver
‐ Torque-controlled tightening with torque wrench
or signal-emitting torque wrench
‐ Tightening with precision mechanical screwdriver
with dynamic torque measuring
‐ Torque-controlled tightening with mechanical screwdriver
‐ Tightening with pulse screwdriver or impact wrench
without adjustment checking device
‐ Tightening by hand, using a spanner without torque
measuring device
total
D E
F
M min.
N
11500 7200
16900 10600
19800 12400
16800 10500
24700 15400
28900 18100
31600 19800
46400 29000
54400 34000
49200 30800
70400 44000
82400 51500
69600 43500
99200 62000
116000 72500
36 / 62
= 0.14.
total
= 0.14
Tightening torque
for screw-connection classes
from table 7
C D
M
A
Nm
44.6 38.4
65.4 56.4
76.5 66.0
76.7 66.1
113 97.1
132 114
186 160
273 235
320 276
364 313
520 450
609 525
614 530
875 755
1020 880
E
34.3
50.4
58.9
59.0
86.6
101
143
210
246
280
400
468
470
675
790