The FHF 55.4 is a manual-winding mechanical movement developed by Fabrique d’Horlogerie de Fontainemelon (FHF). As part of the FHF 55 movement family, this caliber represents a compact, reliable mechanical design tailored for ladies’ wristwatches and slim, time-only dress watches, primarily produced in the mid-20th century.

The “.4” suffix indicates a variant of the base FHF 55 caliber, typically signifying minor layout changes or mechanical adjustments to suit specific case designs or production requirements.

Technical Specifications

• Type: Manual winding

• Size: 6¾ x 8 ligne (approx. 15.3 mm x 18.1 mm)

• Height: Approx. 3.0 mm

• Jewels: 17

• Frequency: 21,600 vibrations per hour (vph)

• Power Reserve: Approximately 42 hours

• Functions: Hours and minutes (no seconds)

Design Characteristics

The FHF 55.4 is a minimalist movement designed for small, elegant watches. Key features include:

• Two-hand layout (no seconds), keeping the movement thin

• Shock protection (Incabloc in most later examples)

• Compact gear train layout, optimized for longevity in slim cases

• Efficient manual winding, intended for daily use in practical, stylish watches

The ".4" version typically included adjustments in bridge layout or stem position for flexible casing options.

Use in Watchmaking

The FHF 55.4 was widely used in:

• Ladies’ gold and steel dress watches

• Small Swiss-made time-only wristwatches

• Rectangular, oval, or tonneau-shaped cases

• Private-label and export-market watches from the 1950s–1970s

Its slim form and mechanical reliability made it a popular choice for fashion-forward and affordable watches alike.

Watchmaker’s Perspective

Watchmakers appreciate the FHF 55.4 for:

• Ease of servicing, with a straightforward, robust layout

• Strong parts compatibility with other FHF 55-family calibers

• Reliable long-term operation with regular maintenance

• Good presence in the vintage repair market

Despite its small size, the movement remains durable and capable, often found in working condition even after decades.

Conclusion

The FHF 55.4 is a prime example of FHF’s mastery in compact Swiss movement design. Built for elegance and functionality, it powered thousands of slim wristwatches during a key period in Swiss watchmaking. Its simplicity, reliability, and adaptability continue to make it a valuable caliber in vintage horology today.