H-31
Automatic Chronograph
The Hamilton H-31 is derived from the Valjoux 7753, while the H-21 is based on the 7750, both offering a 60-hour power reserve. Modifications include an optimized kinematic chain, the removal of the escapement regulator to enhance reliability, an upgraded mainspring, and a distinctively skeletonized H-shaped rotor with aviation-inspired cutouts.
Caliber Details
- Manufacturer
- Hamilton
- Base Movement
- ETA 7753
- Type
- Automatic Chronograph
- Frequency
- 28800 vph
- Power Reserve
- 60 h
- Jewels
- 27
- Diameter
- 30.00 mm
- Display
- Analog
- Hands
- Hours, Minutes, Small Seconds
