MST 522,  523 
Ligne12''' 12'''

Remarks: The final in-house MST automatic. MST522/523 are based on the manual wind MST 520/521 with a bolt on automatic module.
 
Production period: 1973-76

Jewels: 17
Beat: 21600
Winding: automatic
Manufacturer: MST
Hand sizes:
Hour:150
Minute: 90
Second: 25
  
Stem tap size: N/A

Variant:
MST 522 12''' (26mm) direct sweep seconds, date
MST 523 12''' (26mm) direct sweep seconds, date, day

Common parts/Interchange
Balance Staff:
MST part number:7535,  interchanges with MST: 520, 521, 522, 523
Mainspring:
MST part number:1309 interchanges with MST: 520, 521, 522, 523
Strength: 0.112
Height: 1.30
Length: 380
Watches in my collection with the MST523:

All text and images are either © Kris Bubendorfer 2011-15 or © Roamer Watch Company.