Seiko 5106-8010
The 5106-8010 is a Seikomatic-P from Daini Seikosha, made from about 1967 to 1969, in a round case with long lugs. The dial in these photographs reads SEIKOMATIC-P and 33 JEWELS over the Daini mark, with an applied SEIKO, a double index at 12, faceted applied batons, dauphine hands, a day-date at 3 and the dial code 5106-8010T at the bottom edge. The 5106A is a 33-jewel automatic at 19,800 bph that hacks and hand-winds, and its day and date change instantly at midnight, where most Seiko automatics of the period roll over gradually. Pressing the crown in advances the date. The submitter dates this example to June 1967.
| Caliber | 5106 |
|---|---|
| Years | 1967 to 1969 |
| Line | Seikomatic |
| Function | Dress |
| Sub-line | Seikomatic-P |
| Case size | 36mm |
| Lug width | 19mm |
| Crystal | acrylic |
| Factory | Daini |
How do you set the date on a Seikomatic-P 5106-8010?
With the crown pushed home, press it in and the date advances one step. Avoid doing it in the hours around midnight while the calendar is changing over. The day has no quickset and is set by running the hands through midnight.
How does the day-date change on the 5106?
The 5106A changes both day and date instantly at midnight. Most Seiko automatics of the late 1960s use a gradual change that takes several hours to complete.
