This section of the museum shows how spiral springs were made by Junghans. Since it is quite technical, I will simply add the descriptions by the museum.

Wire drawing - explanation see below


Wire rolling


Coiling


rolling, turning and sawing

Riveting


Manual inspection of the springs


Calibration with a watch timing instrument


electronic testing of the number of strikes


Now we are moving down another floor and have a look a the watches actually made by Junghans - check part 4 of the visit

End of Part 3
I noticed the same as you - same owner for Junghans and Carl Haas.
I noticed that a few years back Junghans produced some high-end limited editions with what seems own movements (not sure they were developed inhouse or based on another movement) . I presume for those exclusive movements, they would have used Carl Haas balance springs.
regards
Stefan
