Seiko 5126-8090
The 5126-8090 is a Seiko 5 Sports from Daini Seikosha, made in 1968 and 1969, with the 23-jewel 5126 automatic and a day-date at 3. The dial reads SEIKO 5, SPORTS, WATER 70 PROOF and 23 JEWELS over the Daini mark, on a silver sunburst with a black block minute track, applied markers and a red lollipop seconds hand. The bezel is matte steel with black hour blocks and a lume pip, on a cushion case sold in the Japanese market. The submitter notes the original bracelet is hard to find, so expect most examples on replacement straps.
| Caliber | 5126 |
|---|---|
| Years | 1968 to 1969 |
| Line | Seiko 5 Sports |
| Function | Diver |
| Case size | 38mm |
| Crystal | Hardlex |
| Water resistance | 70m |
| Factory | Daini |
How can I read the serial number on a vintage Seiko?
The first digit of the caseback serial is the last digit of the production year, and the second is the month, using 1 to 9 for January to September and O, N and D for October to December. A serial starting 85 dates to May 1968, which matches the example photographed here.
