Rolex Oyster Perpetual Officially Certified chronometer

The Perpetual movements that equip the Oyster models play a key role in the reputation for excellence of Rolex watches. These self-winding mechanical movements, all rigorously certified as chronometers by the Swiss Official Chronometer Testing Institute (COSC), are entirely designed and manufactured by Rolex based on common characteristics. These ensure high performance and adherence to uncompromising requirements in terms of precision, reliability, shock-resistance, efficient self-winding and ease of maintenance.

BALANCE WHEEL WITH VARIABLE INERTIA
Equipped with gold Microstella nuts, the large balance wheel allows high‑precision regulating and offers great stability.

HAIRSPRING WITH ROLEX OVERCOIL
The outermost coil of the hairspring is curled towards the centre to counter the effects of gravity. This allows perfectly balanced and concentric (isochronous) oscillations of the balance wheel-hairspring assembly and contributes to greater chronometric precision whatever the position of the watch.

OPTIMAL FREQUENCY
A frequency of 28, 800 beats per hour (8 per second) allows optimal conciliation of the oscillator’s precision and peerless reliability.

TRAVERSING BALANCE BRIDGE
The traversing balance bridge allows stable and precise positioning of the oscillator in order to improve chronometric performance. The bridge’s rigidity greatly improves shock resistance.

SELF-WINDING VIA PERPETUAL ROTOR
Invented by Rolex in 1931, this ingenious mechanism consists of a half‑moon-shaped oscillating weight rotating freely in both directions on its axle under the impetus of the wearer’s wrist. It keeps the mainspring under continuous tension and thus provides the watch with a constant and stable source of energy.

HIGH-PERFORMANCE LUBRICANTS
The quality of the lubricants is of prime importance for the proper functioning of a mechanical movement. Rolex has developed exclusive new lubricants, synthesised in‑house, whose useful life and stability over time have been considerably improved.

REFINED FINISHING
Although the Perpetual movements are accessible only to Rolex-certified watchmakers using specific tools, they are decorated in the finest watchmaking tradition. The plates and gear trains are circular-grained, the bridges satin‑finished, circular-grained or snailed, the screw heads are mirror-polished and all edges are bevelled.