6217-8001, 1967
6215-7000, 1967
6159-7000, 1968
5606-7060, 1968

Seiko Quartz Astron 35SQ – Worlds First Quartz Watch, 1969
In the latter half of the 1950s watchmakers were vying to outdo one another in the area of wristwatch accuracy. So it was, in 1959, that Epson launched the “59A Project,” a program to develop a next-generation, high-accuracy, battery-operated wristwatch. The project team members researched several types of battery-operated watch structure — spring balance, tuning fork and quartz. Eventually, however, they began to concentrate on the target of developing a quartz timepiece in a transportable size. This happened to coincide with a program to develop an official timekeeping device for the Tokyo Olympic Games, and synergies between the two programs helped to accelerate that research, leading to the development of the Seiko Crystal Chronometer QC-951. Meanwhile, the company announced in 1966 that it had developed a pocket-watch style quartz prototype. The following year, it announced the development of a prototype quartz wristwatch. The prototypes came away from the prestigious Neuchatel Observatory chronometer contest, winners. Finally, in 1969, came the commercialization of the world’s first quartz watch, the Seiko Quartz Astron 35SQ.
- Center second: One step per second
- Outer diameter 30.00 mm T
- Thickness 5.30 mm (battery unit 6.10 mm)
- Driving method: Crystal oscillation circuit controlled stepping motor
- Vibration frequency: 8.192 Hz
- Accuracy: Room temperature (+4°C to +36°C)
Daily rate ±0.2 sec
Monthly rate: ±5 sec. - Battery life: 1 year or longer
- Jewels: 8
- Price: ¥450,000 (18-karat solid gold case)
Source: Seiko Epson, Astron pdf
7016-8000, 1972
0614-5000, 1973

6139-6002, 1975
6138-8020, 1976


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