Omega cal 5xx movement

 The Omega Caliber 5xx family is a legendary line of full-rotor automatic mechanical watch movements introduced in the mid-1950s. Known for their rugged architecture, reliability, and precision, these calibers formed the backbone of Omega's golden age, powering iconic vintage pieces like the Omega Constellation and Omega Seamaster. [1, 2, 3, 4].

Production Run :7 million

High grade !

Restorable ! 150 components.  Parts are available, but it would be from a donor.... about $1000AUD. 

The Omega Caliber 5xx family (specifically the 550, 551, 552, 561, 564, and 565)

Key Features & Design

Full-Rotor Automatic: Transitioning away from earlier "bumper" automatic movements (like the Cal. 350 series), the 5xx family utilized a full 360-degree oscillating rotor for smoother and more efficient bi-directional or unidirectional winding. [1, 2, 3]. This rotor is often the hardest part to find if it needs to be replaced.
High Build Quality: Built with durable bridges, fine-adjustment regulators (often featuring a swan-neck or micrometer-style regulator), and robust jewel counts (typically 17 to 24 jewels). [1, 2]
Beat Rate: Most run at a traditional vintage frequency of 19,800 vibrations per hour (2.75 Hz) with a power reserve of around 48 hours. [1, 2]
Chronometer & Standard Variants: Many versions were officially certified chronometers adjusted to multiple positions and temperatures, while others served as reliable time-only or date-display workhorses. [1, 2, 3]
screwed balance wheel.

Notable Calibers in the 5xx Series

Caliber 500 / 501 / 505: Early generations introduced in the mid-1950s (starting around 1955), featuring options like center-seconds, date functions, and chronometer specs (Cal. 505). [1]
Caliber 550 / 551 / 552: Widely used time-only automatic movements from the late 1950s through the 1960s. The Cal. 551 is a chronometer-grade version, while the Cal. 552 is a 17-jewel non-chronometer variant. [1, 2]
Caliber 561 / 564: Date-display automatic chronometer movements, with the later Cal. 564 introducing a practical quickset date feature. [1, 2]
Caliber 565: One of the most popular and user-friendly date calibers of the era, famous for its crown-pull quickset date mechanism (pulling the crown past the time-setting position advances the date). [1]

Legacy and Serviceability

Vintage watchmakers and collectors widely praise the 5xx family as some of the finest automatic movements ever mass-produced. They are generally straightforward to service, and replacement parts—such as the wear-prone brass rotor pinion—remain available from specialty horology suppliers.

..........

When it comes to clones or physical copies, there are no true, exact Chinese or 1:1 "clone movements" for the vintage Omega Caliber 5xx series.

1. Why Aren't There Clone 5xx Movements?

While modern Omega movements (like the Caliber 8800 or Co-Axial series) and many Rolex calibers are heavily replicated with dedicated Chinese clone movements, the vintage 5xx series remains untouched by factory cloning operations for a few practical reasons: [1, 2]

The Cost-to-Profit Ratio: Modern factories focus their engineering power on cloning high-demand, high-margin modern luxury movements. Because vintage Omega watches containing the 5xx series are relatively affordable compared to modern sports watches, there is no financial incentive to replicate an intricate 1960s movement from scratch. [1]
Production Complexity: Features like the signature swan-neck regulator, the unique push-pull quickset mechanism of the Caliber 565, and the high-grade copper/rhodium plating require a manufacturing setup that low-cost replica operations cannot easily mimic for profit. [1, 2, 3, 4, 5]

2. What to Watch Out For (The "Fake" Danger Zones)

Even though there are no exact structural copies of the movement itself, you still have to be highly vigilant when buying a Caliber 5xx watch. Instead of modern exact clones, the secondary market faces different issues:

"Frankenwatches" (Parts Swapping): This is the most common issue. Unscrupulous or amateur sellers regularly swap parts within the 5xx family. For example, because parts are highly interchangeable, someone might take a non-chronometer movement (like a Cal. 552) and fit a chronometer-engraved bridge from a Cal. 551 or 561 to artificially boost a watch's value. Always verify that the case reference number aligns with the proper movement version using archival data. [1, 2, 3, 4]
Vintage Fakes with Baseline "Ebauche" Movements: In the 1960s and 70s, counterfeiters did exist, but instead of making a 1:1 clone of the movement, they used cheap, generic base movements (such as low-grade Swiss or Asian ETA-style ebauches) and crudely stamped or engraved "Omega" onto the rotor. If you open a case back and don't see the beautiful copper-pink finish, the proper alignment, or the 24-jewel architecture, it is an old counterfeit. [1, 2]
Modern Counterfeits of Vintage Watches: Occasionally, modern replica factories try to replicate highly coveted vintage models (like the Seamaster 300 or specific Constellation Pie-Pans). However, if you open the back of these modern fakes, you will find modern low-end automatic movements (like a Miyota 8215 or a Seagull ST16) hidden under a crudely decorated plate, rather than a true 5xx architecture. [1, 2]

Summary: You do not need to worry about a highly deceptive, 1:1 Chinese clone of a Caliber 565 or 561. Instead, protect yourself by focusing on originality—ensuring the dial, case, and specific 5xx caliber version all historically belong together

...

...