Seiko 6138 Movement Details

Seiko caliber 6138 is an automatic (with hand winding) watch movement produced from around 1969.

Sub-brands: Speed Timer
Power reserve:45 hours
Day / date?Day + date
GMT / world time?No
Rate:21,600 bph
Number of jewels:21 or 23
Lift angle:54.5º
Size / diameter:12" or 27mm
Stem code: 354616
Balance wheel code: 310611
Mainspring code: 401616
Development division:Suwa (Nagano)
Notes:Based on cal. 6139 movement but with an added chronograph hand to measure elapsed hours. It has a column wheel and vertical clutch for more precise stopwatch measurement.
PDF guides: Technical guide for 6138B
Technical guide for 6138A
Related movements: 6139