Eterna Calibre 1025S: A Vintage Gem for Enthusiasts
The Eterna Calibre 1025S stands as a pinnacle of mid-20th-century Swiss horology, cherished by vintage watch collectors and hobbyist watchmakers for its innovative automatic winding and robust construction. Produced in the 1960s-1970s, this self-winding movement exemplifies Eterna’s pioneering ball-bearing rotor technology, delivering smooth, reliable performance in dress watches and sports models alike. Its compact design and serviceability make it ideal for restoration projects.
History and Innovations
Debuted as part of Eterna’s Eterna-Matic lineup, evolving from Calibre 1025 with enhancements like improved shock protection.
Featured the revolutionary 5-ball-bearing rotor system, minimizing friction for bi-directional winding and exceptional efficiency.
Known for “fit-and-forget” reliability, often running weeks on wrist motion alone during its era.
Technical Specifications
Type: Automatic mechanical, self-winding with sweep seconds.
Jewels: 25 high-quality synthetic rubies for friction reduction.
Frequency: 18,000 vibrations per hour (2.5 Hz), balancing smoothness and longevity.
Diameter: 11.5 lignes (25.6 mm), fitting 34-38 mm cases perfectly.
Height: 4.6 mm, enabling slim profiles under 10 mm total.
Power reserve: Approximately 47 hours, impressive for vintage autos.
Functions: Hours, minutes, central seconds; optional date quickset.
Shock protection: Eterna-U system, safeguarding balance from daily knocks.
Rotor: Polished, heavy metal with low-wind noise and bidirectional efficiency.
For any Watch Spare Parts inquiry, Email us for rate and availability: [email protected]
Watch Parts Enquiry
* If you are unable to fill out any of the required information fields, please type “N/A”.
Stem, Crown, Hands & Spares might be available for this movement.
Email us for rate and availability: [email protected]
Mobile/WhatsApp: +91- 9841 360 340