Omega 266

Last updated: August 4, 2025
Close-up of a copper Omega watch movement showing gears, screws, and intricate mechanical details.

Brand

Caliber Number

266

Production Period

1952 – 1958

Lignes

13.3”’

Diameter

30.0 mm

Height

4.05 mm

Power Reserve

Unconfirmed

Frequency

18,000 bph (2.5 Hz)

Jewels

17

Escapement

Swiss Lever Escapement

Anti-Shock Device

Incabloc

Hand Count

3 (Hours, Minutes, Sub-Seconds)

Manufacture Region

Unconfirmed

Functions

Manual Winding, Small Seconds

Omega 266 Description

The Omega 266 is a widely produced manual-wind caliber from the 26x series, the small-seconds branch of the famed 30mm movement family. Produced from 1952-1958, it is a direct descendant of the original 30T2 caliber and predecessor to the Cal. 267. This robust and reliable workhorse powered a vast number of classic Omega dress watches with a traditional sub-seconds dial.

Watches Using The Omega 266 Caliber

A wristwatch with a brown leather strap, silver case, and a cream and black dial featuring gold Arabic numerals, the Omega logo, and a small seconds subdial at 6 o’clock—this is the classic Omega Seamaster 2937.
Seamaster

Omega Seamaster 2639

1949-1955
36mm