Siemens Maxum II Reference Manual page 50

Electronic Compartment Component Descriptions and Maintenance Procedures
2.3 System Controller Version 2.1 (SYSCON2.1)
Figure 2-20
50
Early SIB3s
with nuts on
threaded studs
securing the CAC3
Mounting the CAC3 on the SIB3
Current SIB3s have screws
in nuts swaged into the board
to secure the CAC3
Maxum II Reference Manual
Manual, 7/2017, 2000596-001