Rolex A260

Last updated: July 26, 2025

Brand

Rolex

Caliber Number

A260 (also Cal. 720/730)

Production Period

1945 – 1953

Lignes

10 ½”’

Diameter

23.7 mm

Height

Thick (necessitated “Bubbleback” case)

Power Reserve

Unconfirmed

Frequency

18,000 bph (2.5 Hz)

Jewels

17 or 18

Escapement

Swiss Lever Escapement

Anti-Shock Device

Variable / Optional for the era

Hand Count

3 (Hours, Minutes, Sweep Seconds)

Manufacture Region

Unconfirmed

Functions

Automatic Winding, Sweep Seconds

Rolex A260 Description

The Rolex A260 is a foundational automatic movement from the 1940s and early 1950s, often considered the base caliber of the “Bubbleback” family that includes the A295 and A296. As a non-chronometer, time-only movement, it served as the reliable engine for a wide range of Rolex’s Oyster Perpetual watches. Its design necessitated the characteristic domed “Bubbleback” case to house the self-winding rotor, making it a cornerstone of Rolex’s establishment of the modern automatic watch.