Quattro's deep dive into the Frédéric Piguet Caliber 21 illuminates its foundational role in ultra-thin watchmaking. This article, inspired by marcobermann, meticulously traces the movement's history and its pervasive influence across numerous luxury brands. For collectors and enthusiasts, understanding the Caliber 21 is crucial to appreciating the lineage of many iconic, slender timepieces.
The idea for this article was suggested to me by marcobermann, whom I thank wholeheartedly for drawing my attention to the little-known importance and major influence of the Frédéric Piguet Caliber 21.
This is, in fact, the ultra-thin, hand-wound caliber that lies, directly or indirectly, behind many, if not almost all, ultra-thin manual-winding calibers used by various brands during the 20th century and even more recently.
Here, then, is its history and its offspring, as I have been able to reconstruct them based on two articles:
THE CREATION OF CALIBER 21
Caliber 21 was created in 1925, after 15 years of development, by Henri-Louis Piguet (1867-1931 - 1st photo below), the son of Louis-Elisée Piguet (1836-1924 - 2nd photo), who founded in 1858 in Le Brassus what would later become Frédéric Piguet SA under the direction of Frédéric Piguet (1906-2001), son of Henri-Louis and grandson of Louis-Elisée.
credit: Famille Piguet
Originally dubbed the caliber 99, the ultra-thin movement measured just 1.69 mm thick, with a 20.4 mm diameter, 18 jewels, a 2.5 Hz beat rate, and a 42-hour power reserve.
One of the features which enabled such a thinness was the use of a “hanging barrel”, the barrel and ratchet wheels being supported only from one side, eliminating the upper movement bridge traditionally used to hold the crown and ratchet wheels in place (the ratchet wheel being the one that sits atop the mainspring barrel).
credit: swisswatch-parts
In 1955, after some key upgrades, including a redesigned escapement beating at 3 Hz, revised bridges, and the addition of (much needed) shock protection, the movement was renamed the caliber 21. These modifications increased the thickness slightly to 1.73 mm.
credit: vintage watches 4 u & Frédéric Piguet SA
The caliber 21 served as the base model for many ultra-thin calibers, either directly or indirectly:
- Direct link: calibers like the Patek Philippe 175 or 177 or Rolex caliber 650 used Frédéric Piguet 21 blanks.
- Indirect link: calibers like the Vacheron Constantin 1003 or the Audemars Piguet 2003 used blanks of the Jaeger-LeCoultre caliber 803, which was itself deeply inspired by the FP21.
Let's have a closer look.
SOME DIRECT DESCENDANTS (by alphabetical order)
a/ BLANCPAIN 21
Blancpain was
acquired in
1982 by
Jacques Piguet, son of Frédéric, and director of Frédéric Piguet SA since 1977.
credit: watches of knightsbridge
b/ IWC caliber 171
credit: Lunar Oyster
c/ Omega caliber 700
credit: watchesulike & horlogeforum.nl (pdf file can be downloaded here)
d/ Patek Philippe calibers 175 & 177
Caliber 175 powering reference 3520
credit: Bukowskis
Caliber 177 powering reference 3667
credit: Goldammer
e/ Rolex caliber 650 (powering reference 9578, here)
credit: ichigo_ichie
SOME INDIRECT DESCENDANTS
a/ Jaeger-LeCoultre caliber 803
The JLC 803 arrived in 1946, exactly 21 years after the introduction of the Frédéric Piguet caliber 21 and this doesn't come as a surprise, because patents are protected for 20 years in Switzerland.
This movement, deeply inspired by the FP21, but only 1.64 mm thick, was the direct base model for the Audemars Piguet cal. 2003 and the Vacheron Constantin cal. 1003.
credit: amanico (image borrowed from this article)
b/ Audemars Piguet caliber 2003 (powering reference 5043BC, here)
credit: Fratello
b/ Vacheron Constantin caliber 1003 (powering the reference 33155, here)
credit: Hodinkee
LASTLY, A MODERN REDESIGN: THE 21.01 "PROJECT 21" by MING
Tantalum case: 35 x 6.9 mm
Thanks for reading.
Best, Emmanuel
