Gone are the days when the weight of a watch was worth the promise of solidity. The current trend is towards lightness. Without sacrificing quality. Quite the contrary.
This craze for featherweight references was confirmed at the recent Watches and Wonders show in Geneva. And especially in the premium segment. “Lightening is not always the priority objective for brands, specifies Sébastien Thibaud, university professor and researcher at SupMicroTech ENSMM, in Besançon (Doubs). It is often the consequence of the choice of new materials. Indeed, some metals do not comply with Reach regulations or RoHs standards (1). As a result, they no longer meet current environmental criteria.” Hence the arrival on the market of titanium-based alloys, whose density is two to three times lower than that of stainless steel – for equivalent mechanical properties – and biocompatible.
As early as the 1980s, the IWC manufacture was one of the first to introduce this metal into the watch industry. It highlights it today on a variation of its Ingenieur Automatic 40 model, which revisits the audacious aesthetic codes of the 1976 version, designed by Gérald Genta. Same choice for Zenith, with its Defy Revival Shadow reference, crafted in titanium with a matte finish. The watch pays homage to a 1969 design, identifiable by its angular case and “ladder” bracelet, designed at the time exclusively for Zenith by the French chain manufacturer Gay Frères. It is also in titanium that the ProPilot X Kermit Edition by Oris was made, a special edition inspired by the famous green puppet.
Ceramics and amorphous metals
Another material that has the wind in its sails, high-tech ceramics. Light and scratchproof, it spreads on glasses, cases and bracelets. Rado and then Chanel have made it their trademark. This material is chosen when it comes to countering the problems of wear and friction, for aesthetic reasons and for its low weight. Not to mention the arrival of new technologies, such as additive manufacturing and, in particular, 3D printing, which promotes the reduction of metal or ceramic structures. “With some exceptions, watch brands are not able to develop these avant-garde materials alone, emphasizes Sébastien Thibaud. Generally, research centers or metallurgists are responsible for supporting them in their quest for innovation.” At the moment, the teacher-researcher is also working on the use of biosourced and recycled materials, which are particularly popular.
To reduce the weight of a watch, its movement must also be taken into account. In addition to exteriors, the Grenoble-based start-up Vulkam endeavors to manufacture watch components in amorphous metal alloys, with mechanical, physical and chemical properties superior to those of traditional metals. The young company already collaborates with 80% of watchmaking houses, for which it develops prototypes and pre-series. By the end of 2024, it will have set up its factory and is even planning a second production line in 2026.
Composite materials
Another major emerging trend is the use of composite materials and fibers that combine the properties of several components. Thus, the case of the new Hermès 08 is made of braided and aluminized fiberglass, combined with a natural pigment, slate powder.
Brands seek to highlight their own alloys. On the Big Bang Integrated Tourbillon Full Carbon, Hublot combines carbon fiber with Texalium®, a composite material that combines 99.99% pure aluminum and fiberglass, embedded in a special resin that protects it from shocks.
While Richard Mille manufactures cases in carbon TPT® and quartz TPT®, other advanced composite materials, for its RM 07-04 collection, the lightest ever designed for women’s wrists. Velcro® strap included, each watch weighs only 36 grams…
“These materials are more difficult to work with and therefore more expensive, points out Sébastien Thibaud. Moreover, even if they are very efficient, none of them tick all the boxes in terms of resistance, wear, scratches, sealing, resistance to ultraviolet rays.” Lightness at all costs also relies on compromises.
(1) The Reach regulation concerns the use of chemical substances in the European Union; the European RoHS directive on hazardous substances in electrical and electronic equipment.