Frédéric Piguet Caliber 21 – A Masterpiece in Ultra-Flat Watchmaking

The Frédéric Piguet caliber 21 is a vintage 2-hander mechanical watch movement renowned for its ultra-flat design. With a thickness of just 1.73mm, this hand-wound movement is officially classified as ultra-thin and has become a symbol of fine Swiss watchmaking. Development of this caliber dates back to circa 1925.

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Technical Highlights

• Height: 1.73 mm
• Manual winding (2-hand display)
• Ultra-flat construction
• Skeleton version: FP 21P
• Highly decorated with boxed "21" engraving on some models

Watch Brands Using the FP21 Ebauche

Many prestigious brands have used the FP21 as a base movement, often adapting or rebranding it under their own caliber numbers:

• Patek Philippe: Caliber 175, 177
• Rolex: Caliber 650
• IWC: Caliber 171
• Omega: Caliber 700
• Longines: Caliber 310
• Certina: Caliber 20-10
• Zenith: Caliber 53.5
• MING: FP21.M1

Other brands using FP21 without specific caliber rebranding include:

• Piaget
• Blancpain
• Cartier
• Movado
• Bueche Girod
• Ebel
• Bucherer

Movements Based on the FP21 Design

• Audemars Piguet: Caliber 2003
• Piaget: Caliber 9P
• Vacheron Constantin: Caliber 1003
• Jaeger-LeCoultre (JLC): Caliber 803

Legacy and Significance

The FP 21 has become one of the most historic and versatile ultra-flat movements in horology. Its design inspired multiple generations of dress watches, and its precision engineering is admired by collectors and watchmakers alike. It continues to represent the pinnacle of traditional Swiss craftsmanship.

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Detailed Overview on Watch Movements That Changed The World of Watchmaking

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