| Brand | Seiko |
| Caliber Number | 5R65 |
| Movement Type | Automatic |
| Jewels | 30 |
| Diameter | 30mm |
| Height | 5.1mm |
| Power Reserve | 70+ hours |
| Frequency | 32,768 Hz (Hertz = cycles per second) |
| Hand-Windable? | Yes |
| Hacking? | Yes |
| Functions | Hours, minutes, central seconds, date |
| Country of Manufacture | Japan |
| Known Models | SBDB008 |
Seiko caliber 5R65 found in the Seiko Marinemaster Golden Tuna. This movement has 30 jewels, power reserve of 70 hours, consists of 292 parts, and beats at 28,800 vph. It has a column wheel and vertical clutch. Made in Japan.
Some of the topics covered in this caliber listing:
Accuracy
According to Seiko official documentation, they claim that this movement has an accuracy rating of +/- 15 seconds per month in normal operating conditions and temperatures (-10 ~ +60 degrees C).
Power Reserve
The caliber 5R65 has a power reserve of 70 hours. Once the mainspring is fully wound, it cannot be over-wound thanks to a slipping mechanism that prevents the mainspring from over-winding. Watches with this caliber typically have a power reserve indicator on the dial. According to Seiko:
The mainspring of the watch becomes fully wound when it is worn for twelve hours for three to five consecutive days. In a case where you wear the watch for a short period of time each day, observe the power reserve indicator to check the level of the remaining power. If necessary, manually wind the mainspring.
Smoothness
This Spring Drive automatic movement is most notable for it’s super smooth Glide-Motion second hand. You can see it up-close in action here.
Variations
There are two variations of this caliber: the 5R65 with 30 jewels and the 5R64 with 32 jewels. Both of these calibers have the same usage, the difference being that the 5R65 has a central sweeping seconds hand and the 5R64 has a small seconds hand.
Service/Repair
At the time of this post, Seiko calls for all repairs and overhauls to be sent to Seiko Watch Company in Japan for service. They will not provide any movement parts to watchmakers.
Resources:
Note: a photo of this movement is desperately needed to complete this listing. If you have an original photo that can be posted, please let us know.
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