MST 253,  277 
Ligne10.5''' 10.5'''
Cal. MST 253 Cal. MST 277

Remarks: An unusal 10.5 ligne movement in terms of barrel bridge layout. Shares balance, lever, escape, mainsping and many other parts with the MST202. Not considered a variation of the MST202 family as the train gears differ. MST 253 was listed as obsolete in 1933, the 277 was not, probably the 277 was a replacement for the 253.
 
Production period: 1925-1932 (253), 1933- (277)

Jewels: 6, 13 or 15
Beat: 18000
Winding: manual
Manufacturer: MST
Hand sizes:
Hour:150
Minute: 80
Second: 19
  
Stem tap size: 90

Variant:
MST 253 10.5''' (23.40mm) integral winding and barrel bridge
MST 277 10.5''' (23.40mm) separate winding and barrel bridge

Common parts/Interchange
Balance Staff:
MST part number:7438,  interchanges with MST: 202, 229, 242, 253, 271, 277, 303, 337
Mainspring:
MST part number:1232 interchanges with MST: 202, 229, 242, 253, 271, 277, 303, 337
Strength: 1.050
Height: 1.45
Length: 250
Watches in my collection with the MST253:

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