Omega 285

Last updated: July 26, 2025

Brand

Caliber Number

285

Production Period

1958 – 1961

Lignes

13.3”’

Diameter

30.0 mm

Height

5.1 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, Sweep Seconds)

Manufacture Region

Unconfirmed

Functions

Manual Winding, Sweep Seconds

Omega 285 Description

The Omega 285 is a revered manual-wind caliber from the final generation of the brand’s famed 30mm movement family, produced from 1958-1961. As a direct predecessor to the Cal. 286, it is a robust, time-only movement with a sweep-seconds hand. It was a workhorse of its era, famously powering “Seamaster 30” and “Geneve” models, and represents the continuous refinement of the legendary 30T2 SC design.

Watches Using The Omega 285 Caliber

A wristwatch with a black face, gold hour markers and hands, the Omega logo, and the word Seamaster in script. The Omega Seamaster 14390 features a silver case and a light brown leather strap with visible stitching.
Seamaster

Omega Seamaster 14390

1959-1962
35mm
A vintage Omega wristwatch with a brown, slightly speckled dial, gold hour markers and hands, and a tan leather strap, displayed against a plain white background.
Omega

Omega 2640

1949-1958
36mm
A vintage Omega Railmaster 2914 wristwatch with a black dial, white numerals, beige minute markers, and a tan leather strap. The round stainless steel case and silver hands complete this classic timepiece.
Railmaster

Omega Railmaster 2914

1957-1963
38mm