The Tissot caliber 431 is a manual-winding mechanical movement introduced in the 1950s, representing one of Tissot’s efforts to produce reliable, slim, and accurate in-house calibers during the golden age of Swiss watchmaking. Often found in elegant mid-century dress watches, this movement exemplifies the balance of simplicity and mechanical refinement that characterized Tissot's approach to watchmaking in the post-war era.

Overview of the Tissot Caliber 431

The 431 was part of a family of movements used in time-only wristwatches, typically with a small seconds subdial at 6 o’clock. These watches were usually cased in stainless steel or gold-plated cases, with modest diameters ranging from 33 to 36 mm. The design of the movement was compact and efficient, allowing for slimmer watch profiles without compromising durability.

It was commonly paired with clean, minimalist dials—often with baton or Arabic numeral hour markers—emphasizing clarity and classic aesthetics.

Technical Specifications

• Type: Manual winding

• Functions: Hours, minutes, small seconds

• Jewels: 15 (in most variants)

• Frequency: 18,000 vibrations per hour (2.5 Hz)

• Power Reserve: Approximately 40 hours

• Diameter: ~27 mm (approx. 12 lignes)

• Height: ~4.0 mm

• Shock Protection: Basic or none, depending on the production year

• Finish: Brushed or matte plates; bridges often stamped with "Tissot" or caliber number

This movement was built with a Swiss lever escapement, a bimetallic balance, and traditional materials consistent with the era. Its layout was straightforward, prioritizing ease of servicing and long-term reliability.

Maintenance and Servicing

Because the Tissot 431 is now a vintage movement, it requires careful and regular maintenance:

• Service interval: Every 4 to 6 years

• Recommended service tasks:

  • Complete disassembly and ultrasonic cleaning

  • Inspection of gear train, mainspring, and balance pivots

  • Lubrication using modern synthetic oils

  • Timing adjustment in multiple positions

  • Replacement of gaskets and cleaning of the case (if applicable)

While the 431 is relatively easy to service due to its simple structure, sourcing original replacement parts may require using donor movements or working with experienced vintage watch specialists.

Common Wear Points

• Mainspring fatigue is common after decades of use and may reduce power reserve.

• Pivots and bushings in the gear train may show wear if the movement was run dry.

• Balance staff can be fragile and may require replacement if the watch suffered impact.

• Crown and stem may wear, especially if frequently wound or exposed to moisture.

Handling Tips

• Wind gently once per day, stopping when resistance is felt

• Avoid water and moisture—most watches with the 431 were not designed with water resistance in mind

• Keep away from magnetic fields which can disrupt timing

• Store the watch face up in a dry, cool place when not in use

Collectibility and Legacy

While not a rare or high-complication caliber, the Tissot 431 is appreciated for its:

• Mechanical honesty and vintage charm

• Smooth winding and solid construction

• Historical significance as part of Tissot’s mid-century offerings

Watches powered by the 431 are excellent entry-level vintage Swiss pieces, offering timeless design and mechanical reliability at accessible prices.

Conclusion

The Tissot caliber 431 is a testament to Tissot’s craftsmanship during a period of strong Swiss watchmaking tradition. Simple, sturdy, and elegant, it continues to serve collectors and wearers with dependable manual performance. With regular maintenance and thoughtful use, a watch housing the 431 can remain a trustworthy and historically meaningful timepiece for many years to come.