Movement Caliber 311

311 Caliber
311 Caliber Curvex
Gruen 311 Caliber Outline
Family: Curvex
Base Movement:
Some parts interchangeable with:
355 355C
Size (lignes):  7 3/4 "' x 11 "'
Jewels: 17
Year Introduced 1935
Mainspring Size in mm
118 x .105 x 250
Mainspring Interchangeability
311 355 500 501 502
Fingerprint
(Movement Shape and Keyless works parts)
311 Gruen Caliber Fingerprint
Page in Repairer's Reference:  193
 
Style Numbers Used Per Year
311 Style Numbers used Over Time
 
Marking variants

Text orientation flipped
Precision and serial marking on Barrel Bridge versus Precision marking on Train Bridge
311 Caliber Precision on Train Bridge
 
Notes