Seiko Cal. 6R27 is a midrange automatic movement produced by Seiko Instruments Inc. (SII) for Seiko watches. Like other Seiko 6R movements, it is more refined and accurate than the related Seiko 4R series and uses a Spron 510 mainspring. Unlike Cal. 6R15, it is a “Hi-Beat” movement operating at 28,800 A/h and has complications: Date subdial at 6:00 and retrograde power reserve at 9:00. The SARW005 Laurel tribute lacks the central seconds hand of all other 6R movements.
According to Seiko documents, this is a modular movement based on Cal. 6R15 but with a Hi-Beat balance.
Seiko 6R27 Applications
Cal. 6R27 was only used in a few watches. As of 2020 it is found in 3 models.
- 2013 SARW005 – 100th anniversary Laurel tribute
- 2016 SARW027 – 60th Anniversary Presage (limited to 1956 examples)
- Seiko Presage SPB045, SPB091
- Seiko Presage Arita Porcelain Dial SPB093
| Jewels | Components | Speed | Power | 3:00 | 6:00 | 9:00 | |
| 6R15 | 23 | 168 | 21,600 | 50 | Date Window | ||
| 6R20 | 29 | 208 | 28,800 | 45 | Day Subdial | Date Subdial | Clockwise Power Reserve |
| 6R21 | 29 | 208 | 28,800 | 45 | Day Subdial | Date Subdial | Counter-Clockwise Power Reserve |
| 6R24 | 31 | 224 | 28,800 | 45 | Retrograde Day | Retrograde Date | Clockwise Power Reserve |
| 6R27 | 29 | 28,800 | 45 | Date Subdial | Counter-Clockwise Power Reserve | ||
| 6R35 | 24 | 21,600 | 70 | Date Window |