When WCL went hands-on with the Bianchet B 1.618 Grande Date Sapphire at Geneva Watch Days in 2024, we called it one of our favorite sapphire case watches out there. Now, with the UltraFino, Rodolfo and Emmanuelle Festa-Bianchet have made a far more ambitious declaration. This is a complete rethinking of what an independent Swiss tourbillon can be when it trades bulk for discipline. The B 1.618 UltraFino is Bianchet's first ultra-thin design, first automatic movement, and first integrated bracelet. Three firsts in a single release from a brand only five years old. That level of mechanical ambition deserves attention.
Things to Know
The case on the B 1.618 UltraFino Titanium Blue measures 40 mm wide, 47.39 mm long, and just 8.9 mm thick, proportions that immediately distinguish it from Bianchet's earlier Grande Date collection, which measures 43 mm and 14.35 mm thick. The grade 5 titanium case features a curvature from lug to lug that allows the tonneau case to follow the contour of the wrist with the kind of ergonomic fit usually reserved for integrated strap designs.
Despite its thin profile, the Bianchet UltraFino Titanium withstands shocks up to 5,000 Gs and carries a 50-meter water resistance rating, specifications that go well beyond what the haute horlogerie segment typically offers at this thickness. The collection offers two distinct personalities: a skeleton version and a solid-dial version. The Dial version features Bianchet's exclusive Golden Diamond pattern—a modern reinterpretation of the Clou de Paris motif designed entirely with golden proportions. The blue dial is a chameleon, varying in hue depending on the lighting conditions. The opening at 6 o’clock reveals an exquisite flying tourbillon that weighs only 8 grams.
The watch is equipped with a fully integrated titanium bracelet and an additional vulcanized rubber strap, swappable via a release system on the case back that requires no tools. The watch wears very comfortably on the wrist, whether on the bracelet or the strap.
The Movement
Turning the watch over reveals the new calibre UT01, an automatic flying tourbillon movement measuring just 3.85 mm in thickness and weighing only 8 grams. Constructed entirely from Grade 5 titanium, including the bridges and tourbillon cage, the UT01 is among the lightest automatic tourbillons currently in production.
The one-minute flying tourbillon beats at 21,600 vph, with a 2.66 mm cage positioned at six o'clock, and every proportion follows Bianchet's signature application of the Golden Ratio. The solid-gold rotor—over a titanium edge—features 12 interlacing Fibonacci spirals that fully wind the movement in under 12 hours. Back bridges form two concentric golden circles that serve both aesthetic and structural roles, absorbing shocks in extreme conditions. Each movement receives over 15 hours of traditional hand beveling and provides a power reserve of 70 hours.
On the Wrist & Price
The watch sits comfortably and is light on the wrist, weighing 77 grams on its bracelet. What Bianchet has achieved with the UT01 calibre is not trivial. An independent brand delivering a proprietary automatic flying tourbillon at 3.85 mm height in an anti-magnetic titanium architecture with genuine shock and water resistance, places the B 1.618 UltraFino in direct conversation with ultra-thin tourbillon offerings from far larger manufactures. The pricing reinforces the point. If Richard Mille were building this watch, you would be looking at double the price and working out the reasoning afterward.
Sticker Price CHF 55,500—approx USD 70,500. For more information on Bianchet, click here.
