Seiko 66-8050
The 66-8050 is a time-only Seiko from Suwa with no date. The black dial reads SEIKO, WATERPROOF and 17 JEWELS over the Suwa mark, with applied batons doubled at the quarters, polished dauphine hands and a thin red seconds hand. The caseback carries the Suwa mark, the reference 66-8050 and the serial 049285, which dates this example to April 1970. The 66 prefix is the caliber, a 17-jewel movement. The case is about 35mm with 18mm lugs.
| Caliber | 66 |
|---|---|
| Years | 1968 to 1972 |
| Function | Dress |
| Case size | 35mm |
| Lug width | 18mm |
| Crystal | acrylic |
| Factory | Suwa |
How do you date a Seiko 66-8050?
The serial number on the caseback provides the production date. The first digit represents the last digit of the year, and the second digit indicates the month (1-9 for Jan-Sep, O, N, D for Oct-Dec). The 04 prefix on this example dates it to April 1970.
What movement is inside the Seiko 66-8050?
The caliber 66, a 17-jewel time-only movement, which is what the 66 prefix on the caseback refers to. It has no date, so there is no calendar to set or wear out.
