Rolex A296

Last updated: August 4, 2025

Brand

Rolex

Caliber Number

A296 (also Cal. 775)

Production Period

1950 – 1955

Lignes

10.5”’ (base)

Diameter

29.5 mm

Height

Thick (necessitated “Bubbleback” case)

Power Reserve

Unconfirmed

Frequency

18,000 bph (2.5 Hz)

Jewels

17, 18 or 19

Escapement

Swiss Lever Escapement with Breguet Overcoil

Anti-Shock Device

Monorex

Hand Count

3 (Hours, Minutes, Sweep Seconds)

Manufacture Region

Unconfirmed

Functions

Automatic Winding, Sweep Seconds, Chronometer, some with Date

Rolex A296 Description

The Rolex A296, also known as Cal. 775, is a significant early automatic, chronometer-grade movement from the early 1950s. Its thickness, required to house the self-winding rotor, necessitated the iconic domed “Bubbleback” or “Ovettone” caseback. This caliber was the engine in seminal models like the first Submariner (ref. 6200), “pre-Explorer” models (ref. 6150/6298), and early Datejusts, establishing Rolex’s reputation for robust and precise automatic tool watches.