Siemens SIMOTICS S-1FK2 Operating Instructions Manual page 52

Mounting
5.3 Mounting instructions
Flange designs at the gearbox output
Flange mounting of planetary gearboxes NRB, NRBW, NRK, NRKW, NP, NLC, NLCW, and SP+
NRB/NRBW For gearboxes with aluminum output flange, use screws with a maximum property class of 10.9,
assuming that you use 90 % of the screw yield strength.
Gearbox size Mounting
flange
040
060
IM B14
080
120
160
1)
1): Not for NRBW
NRK/NRKW
Gearbox size Mounting
flange
050
070
IM B14
090
120
155 2)
2): Not for NRKW
50
Flange IM B5, e.g. NLC, SP+
Ø circle of
holes
in mm
34
52
70
100
145
Ø circle of
holes in mm
44
62
80
108
140
Flange IM B14, e.g. NRB, NRK, NP
Number of Thread size
threads
M4
M5
4
M6
M10
M12
Number of Thread size
threads
M4
M5
4
M6
M8
M10
Operating Instructions, 09/2023, A5E50494253B AC
Thread depth Property class
of the screws
in mm
6
8
10.9
10
16
20
Thread depth Property class
of the screws
in mm
8
8
12.9
9
20
20
Planetary gearboxes for servomotors