After nine years of research and development, TAG Heuer unveils the TAG Heuer TH-Carbonspring – an innovative hairspring crafted from carbon. The brand had already presented an early prototype back in 2019, but the technology has since been refined and is now ready for series production. This patented hairspring offers three key advantages over traditional metal variants. First, it is unaffected by magnetic fields – a common cause of timekeeping inaccuracy in mechanical watches. Second, it offers improved shock resistance, making it better at absorbing impacts and vibrations. Third, thanks to its extremely low weight, it significantly reduces inertia and therefore energy loss within the movement. Compared with silicon hairsprings, the carbon version also benefits from lower mass. In any case, due to existing patents, only Rolex, Patek Philippe, the Swatch Group and Ulysse Nardin are currently permitted to use silicon hairsprings.
TAG Heuer has filed four patents for its new hairspring, one of which has already been granted. The component is not only a product of the brand’s in-house research and development, but is also manufactured entirely within TAG Heuer’s own facilities. One of the greatest challenges lies in the hairspring’s minuscule dimensions. Production begins with silicon wafers used as a mould, onto which carbon nanotubes are grown via chemical vapour deposition. These hollow structures are then filled with carbon. The key innovation – and the subject of a new patent – is TAG Heuer’s ability to chemically seal the surface, thereby preventing the hairspring from absorbing moisture.
The TAG Heuer TH-Carbonspring makes its debut in two limited-edition timepieces: the Monaco Flyback Chronograph TH-Carbonspring and the Carrera Chronograph Tourbillon Extreme Sport TH-Carbonspring, each limited to just 50 pieces. Both models hail from historic collections that embody TAG Heuer’s deep-rooted connection to motorsport, making them ideal platforms for showcasing this carbon-based technology – originally developed for racing cars and now essential in motorsport engineering.
The cases are made from forged carbon – a material created by compressing finely chopped carbon fibres under high pressure in a mould, rather than weaving them. This technique results in a distinctive, marbled surface pattern. In fact, the bezel, crown, pushers, indexes and even the dials are all crafted from forged carbon. The dials feature a subtle snailing pattern that echoes the spiral form of the hairspring itself. Visible through sapphire casebacks is a new movement decoration: a chequerboard finish composed of alternating vertical and horizontal brushed sections – a visual nod to the woven structure of carbon fibre.
Inside this limited-edition Monaco ticks the in-house calibre TH20-60, equipped with the new carbon hairspring, automatic winding and flyback chronograph function. Its precision is officially certified by COSC, while the power reserve reaches an impressive 80 hours. The signature square case measures 39 mm across and is water-resistant to 100 metres. The watch is worn on a rubber strap with a textile-like texture and a titanium folding clasp. Limited to just 50 pieces, the Monaco Flyback Chronograph TH-Carbonspring is priced at 17,000 Swiss francs.
A flying tourbillon chronograph is one of TAG Heuer’s technical specialties – and this model makes the high complication comparatively accessible. Inside ticks the in-house calibre TH20-61, an automatic movement featuring the carbon hairspring, COSC chronometer certification, and a 65-hour power reserve. The forged carbon case measures 44 mm in diameter and is water-resistant to 100 metres. Like its Monaco counterpart, the watch is paired with a rubber strap featuring a textile-like finish and a titanium folding clasp. Limited to 50 pieces, the Carrera Chronograph Tourbillon Extreme Sport TH-Carbonspring is priced at 40,000 Swiss francs.
