Sellita SW500 Movement: Functions, History, and Interesting Facts

The Sellita SW500 is a Swiss automatic mechanical caliber that represents a robust and precise chronograph platform designed for higher-end watches. This movement is developed and manufactured by Sellita as a replacement and alternative to the well-known and widely used ETA Valjoux 7750, offering reliability, quality, and compatibility with many cases and components.

History
Sellita, established as a leading independent Swiss mechanical movement manufacturer, introduced the SW500 as its own version of the legendary Valjoux 7750 chronograph. This caliber was developed in response to ETA’s restriction of supplying movements to third parties, creating a need for alternatives for many watchmakers. Since its launch, the SW500 has been well received and widely used as the foundation for many chronographs across the market.

Functions and Technical Specifications

• Automatic chronograph with stopwatch function and accuracy of ±10 to ±15 seconds per day (depending on regulation).

• Frequency of 28,800 vibrations per hour (4 Hz), ensuring smooth operation of the chronograph seconds hand.

• Power reserve of approximately 42 hours.

• Displays hours, minutes, chronograph seconds, 30-minute and 12-hour stopwatch counters.

• Date window with quickset feature.

• Contains 25 jewels to reduce friction and wear.

• Movement diameter approximately 30 mm, height about 7.9 mm.

• Manual winding possible via crown.

• Robust and durable construction suitable for demanding conditions.

Interesting Facts

• The Sellita SW500 is a direct successor and competitor to the legendary ETA Valjoux 7750, often called the "workhorse" chronograph.

• Thanks to high compatibility, the SW500 can be used in most cases designed for the Valjoux 7750, simplifying watch production and servicing.

• Popular among many brands seeking to offer high-quality mechanical chronographs without reliance on ETA.

• Sellita emphasizes quality, precision, and reliability, which the SW500 demonstrates in practice.

• Robustness and resistance to shocks and vibrations make this caliber suitable for sports and professional watches.

Summary
The Sellita SW500 is a high-quality and reliable automatic chronograph movement offering features and specifications on par with the ETA Valjoux 7750. Due to its compatibility, performance, and easy serviceability, the SW500 is an ideal choice for watchmakers aiming to provide top mechanical watches with a long service life. This caliber is a great option for anyone looking for a robust and accurate mechanical chronograph.