Seiko 840 Movement Details

Seiko caliber 840 is an automatic watch movement produced from around 1964.

Day / date?Date only
GMT / world time?No
Chronograph?No
Rate:18,000 bph
Number of jewels:30
Size / diameter:28.6mm
Height:4.55mm
Development division:Suwa (Nagano)
Notes:Replaced cal. 830. This movement became cal. 8305.
Related movements: 394 830 8305 8306