Movement Caliber 430

430 Caliber
Gruen Caliber 430 Movement
Family: Veri-Thin
Base Movement:
Some parts interchangeable with:

Size (lignes):  8 3/4 "' x 9 3/4 "'
Jewels:   17
Year Introduced:   1940

Mainspring Size in mm
1.18 x .105 x 247
Mainspring Interchangeability
430 431 435 440 335
(Movement Shape and Keyless works parts)
430 movement fingerprint
Page in Repairer's Reference:  225
Style Numbers Used Per Year
Marking variants

B Series Serial Number
Caliber 430 Movement Serial Number B

Almost entirely interchangeable with the Curvex 440 movement.

Is the "Precision" 17 jewel version of the Veri-Thin 430 family of movements consisting of 430, 431, 435

Gruen states that the 440 Curvex uses the same parts as the 430 except for Ratchet Wheel, however that's a gross summary. Closer examination shows these differences

  • The ratchet wheel's text (mechanically they are the same)
  • The pillar plate has differing caliber stamps
  • The pillar plate on the 440 is "curved"
  • The ratchet bridge with the serial number
  • The train bridge has different text and design but mechanically the same