Movement and technical notes
One of the most interesting features is the Second Setting mechanism. This is different from the normal hacking system found on many later watches. When the crown is pulled into the hand-setting position, the seconds hand does not stop immediately. Instead, it continues moving until it reaches exactly the 60-second / zero position, where it stops automatically.
The user can then set the hour and minute hands and wait for an official time signal. At exactly the beginning of the next minute, the crown is pushed back in and the watch starts again from zero seconds. In practical use the procedure was therefore:
Pull crown → seconds continue to 60 → seconds stop at zero → set the time → wait for the reference signal → push crown in → watch restarts exactly on the minute.
This was particularly useful for railway operation, where several staff members and station clocks needed to be synchronised to the same reference time. Seiko introduced this type of Second Setting system to the Type 19 family in the 1950s.
Diaflex is Seiko’s name for the tough special-alloy mainspring designed to resist breakage and loss of spring strength.
Important Notes
- Dustproof only
- No water resistance warranty is provided
Dimensions
- Width (without crown): 51 mm
- Height (with bow): 72 mm
- Thickness: 16 mm
