Grand Seiko · 9S mechanical
9SA5
A high-beat automatic combining a 5 Hz balance with an 80-hour reserve.
At a glance
- Type
- Automatic mechanical
- Display / complication
- Date
- Architecture
- Dual Impulse Escapement, twin barrels
- Timebase
- 36,000 vph / 5 Hz
- Power reserve
- Approx. 80 h
- Jewels
- 47
Reference sources reviewed 7 November 2026. Published specifications, not independent measurements. Versions and complete-watch specifications can differ; fields without a verified figure are omitted or identified.
What distinguishes it
Look beyond the reference.
The escapement delivers energy to the balance in two ways. Together with twin barrels, it makes a useful case study in balancing a fast rhythm with long running time.
For the enthusiast
Compare 9RA2 carefully: both carry the Grand Seiko name, but only 9SA5 uses a conventional oscillating balance. A higher frequency alone does not guarantee better real-world accuracy.