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ETA 931
Ligne: 19'''
Jewels: 15
Power Reserve: 35 hrs
Frequency: 18000 vph
Type: Manual Wind
Period used: 1925-1930
Diameter: 42.95 mm
Height: 5.3 mm
Hands: 1.80 x 0.95 / 0.26 mm
The ETA 931 is a hunter or open face calibre watch movement. It features a bimetallic screw balance and a Breguet hairspring. The movement is based on an ebauche from FHF Robert. It incorporates a setting mechanism without a setting-lever spring, as per the Swiss Patent 51482 from FHF. The ETA 931 movement offers stem winding and setting, along with a sub-second function. It was in use during the period of 1925-1930.
The ETA 931 features the following functions:
Balance Staff Listing
| Ronda Reference # | Shock System | Buy |
|---|---|---|
| 3309 | Incabloc | Buy staff |
| 2360 | Shock Resist | Buy staff |
| 3112 | Supershock | Buy staff |
Mainspring Listing
| Dimensions | GR Reference # | End Type | Buy |
|---|---|---|---|
| 1.30 x 0.080 x 280 x 7.5 mm | GR3204 | Manual | Buy mainspring |
Incabloc Part Listing
| Block # (Top/Bottom) | Cap Jewel # (Top/Bottom) | Spring # (Top/Bottom) |
|---|
KIF Part Listing
| Block # (Top/Bottom) | Cap Jewel # (Top/Bottom) | Spring # (Top/Bottom) |
|---|
Documents
Parts Listing
| Part Description | Reference # | Alternate | Buy |
|---|
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