|Caliber Number||5Y23, 5Y23A|
||19mm x 22mm|
||371/370 (SR920SW), 1.55V|
||Step motor (load compensated driving pulse)|
||1.1mm / .65mm / .18mm|
|Functions||Central hours; central minutes; central seconds; day-date at 3:00|
|Country of Manufacture||Japan|
||Seiko 5Y23-7089 (Add your watch to the comments below…)|
The Seiko caliber 5Y23A is a vintage quartz movement with a day-date calendar complication. Technical documentation for this caliber was found dated June 1988, so this movement was produced at least that long ago.
The cal. 5Y23A shares the same technical documentation as calibers 5Y22A, 5Y30A, 5Y31A, 5Y32A, and 5Y39A.
Although they are all based on the same 5Y framework, there are various differences between them including the following:
- 2-Hander – 5Y30A, 5Y39A
- 3-Hander – 5Y31A, 5Y32A, 5Y22A, 5Y23A
- No Day or Date – 5Y30A, 5Y31A
- Date – 5Y32A, 5Y39A, 5Y22A
- Day-Date – 5Y23A
The heights and diameters also vary slightly between the calibers, therefore they may not be fully interchangeable.
- 24mm Outside Diameter – 5Y30A, 5Y31A, 5Y32A, 5Y39A
- 25.4mm Outside Diameter – 5Y22A, 5Y23A
- 2.1mm Thick – 5Y30A, 5Y31A
- 2.5mm Thick – 5Y32A, 5Y39A
- 2.7mm Thick – 5Y22A, 5Y23A
Watches with this movement:
The example of caliber 5Y23A pictured above was found in a Seiko watch with a case number of 5Y23-7089.
Submitted by JM