Omega Caliber 231: A Forgotten Foundation of Mid-Century Watchmaking

The Omega Caliber 231 is one of the lesser-known but historically meaningful manual-wind movements from Omega’s rich mechanical catalog. Produced in the late 1940s and early 1950s, this caliber was designed with functionality, simplicity, and reliability in mind—key traits during an era when Omega was establishing itself as a global leader in precision timekeeping.

Though it doesn’t carry the fame of the 30T2 or 321 calibers, the 231 was a workhorse that contributed to Omega’s post-war success and was a building block for more refined hand-wound models to come.

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Movement Overview

The Omega 231 is a manual-winding mechanical movement, characterized by its compact size and time-only functionality.

Technical Specifications:

• Type: Manual-wind

• Diameter: Approximately 23.7 mm (10.5 lignes)

• Height: Around 3.6 mm

• Jewels: 15

• Frequency: 18,000 vibrations/hour

• Power Reserve: ~42 hours

• Functions: Hours, minutes, and small seconds

• Shock Protection: Incabloc (in later examples)

The movement was generally found in slim dress watches, marketed for both men and women during the early 1950s. It was never part of a high-complication series, but rather positioned as a reliable, no-frills caliber ideal for elegant and affordable timepieces.

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Practical and Versatile

The 231’s modest size made it ideal for watches with 32mm to 34mm cases, a standard for the time. Many of these watches were housed in stainless steel or gold-plated cases, often with snap-on casebacks and minimalistic dial designs.

Dial layouts typically featured:

• Slim applied hour markers or printed numerals

• Small seconds subdial at 6 o’clock

• Leaf or dauphine hands

• Uncluttered, symmetrical aesthetics

Omega positioned these watches as accessible daily wearers, reliable enough for professionals and refined enough for formal occasions. The thinness of the movement also allowed for slim cases, which remain highly wearable by today’s vintage standards.

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Service and Reliability

The Omega Caliber 231 was built to be easily serviced, using a traditional layout and proven Swiss lever escapement. Though production was limited compared to larger families like the 30mm series, the movement was well-constructed, and examples continue to perform well today when maintained properly.

Spare parts can still be sourced through vintage watchmakers and donor movements, particularly since Omega maintained high component standardization across its calibers during this era.

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Collector Perspective

From a collector’s point of view, the 231 is appealing for several reasons:

• Historically significant as a post-war movement

• Affordable entry point into vintage Omega collecting

• Timeless aesthetic and case proportions

• Under-the-radar charm

It may not be a chronometer or feature a date complication, but the 231 captures the spirit of Omega’s commitment to mechanical excellence in even its most modest calibers.

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Final Thoughts

The Omega Caliber 231 represents the quiet backbone of Omega’s mid-century watchmaking. With its straightforward design, smooth manual-wind action, and dependable accuracy, it remains a satisfying piece of horological history. For those seeking a reliable and stylish vintage Omega without breaking the bank, a watch powered by the 231 offers enduring value and classic appeal.

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