Main:
- Internal thread
Secondary:
- Spacer
- Assembly of two sheets
(RE type)

A welded nut:
- a long, complex welding process
- thread coaxiality not very precise
- an unattractive solution
Workpiece tapping:
- a long, complex and not very accurate tapping process
- low mechanical resistance of thread (too few threads)
Nut and bolt:
- assembly is cumbersome because it necessitates holding both the nut and the bolt