Engineering The Impossible: Inside The Bvlgari Octo Finissimo Ultra Tourbillon
With the launch of the Octo Finissimo Ultra Tourbillon, Bvlgari sets a new benchmark in ultra-thin mechanical watchmaking. At just 1.85mm thick, this timepiece becomes the world’s thinnest tourbillon-equipped watch, a title that emphasizes not only the brand’s continued innovation but also its ability to reimagine the limits of traditional horology.
A New Evolution in the Octo Finissimo Line
Bvlgari’s Octo Finissimo collection is no stranger to record-breaking accomplishments. The Ultra Tourbillon builds upon a legacy that includes previous milestones like the 1.95mm-thick Octo Finissimo Tourbillon (2014), the 2.23mm Octo Finissimo Automatic, and the world’s thinnest perpetual calendar. With the Ultra Tourbillon, Bvlgari advances from thin movements to fully integrated ultra-slim wristwatches.
Ultra-Slim Construction and Technical Design
Central to the Octo Finissimo Ultra Tourbillon is the BVF900 caliber, a hand-wound mechanical movement measuring just 1.50mm in height. Operating at a frequency of 4Hz (28,800 vibrations per hour), the caliber provides a 42-hour power reserve. Notably, the movement is directly integrated into the case structure—a critical factor in achieving such extreme thinness.
The watch measures 40mm in diameter and features an openworked tourbillon regulator positioned at 6 o’clock. This tourbillon is engineered to rotate once per minute, enhancing accuracy by averaging out gravitational effects.
Materials and Architecture
The case architecture is particularly complex, incorporating also titanium for the bezel, lugs, and integrated bracelet, while the mainplate is crafted from tungsten carbide. This material was selected for its high density and rigidity, essential for maintaining structural integrity at minimal thickness.
A total of eight patents were filed to support the development of the Octo Finissimo Ultra Tourbillon, each addressing a specific technical challenge. These include a differential time display system, which allows the watch to maintain readability while minimizing mechanical layers. The integration of the case middle and movement plate into a single structural component eliminates redundant thickness and enhances rigidity.
Another patent covers the bi-material caseback, which combines materials to achieve both strength and lightness without compromising on thinness. The crystal mounting technique is also newly developed, allowing the sapphire crystal to be secured with extreme precision at minimal height.
In terms of the movement itself, Bvlgari introduced a novel barrel architecture designed to optimize power delivery within a drastically reduced volume. The oscillator module also underwent a complete redesign to ensure consistent performance in such a limited space. Additional patents relate to the modular construction of movement components—streamlining assembly while maintaining structural integrity—and to the ultra-slim bracelet, which is only 1.5mm thick, including its integrated clasp, yet remains robust and flexible.
Dual Crown Operation
The time-setting and winding mechanisms are separated and positioned on opposite flanks of the case. The right-side crown is dedicated to time-setting, while the left-side crown serves for manual winding. Both are constructed in stainless steel and designed to sit flush with the case for a seamless silhouette.
Display and Finishing
The dial is reduced to essential elements. Rhodium-plated hands contrast against a sandblasted brass dial plate. Legibility remains functional, despite the minimalist aesthetic, in keeping with the high-concept mechanical nature of the watch.
A Limited Production Milestone
Only 20 pieces of the Octo Finissimo Ultra Tourbillon will be produced, each priced at €750,000. Given the degree of technical complexity, precision engineering, and patent-backed innovations involved, the timepiece stands as a demonstrative statement of Bvlgari’s position at the forefront of ultra-thin haute horlogerie.
More information here.
General Specifications:
Brand: Bulgari
Model: Octo Finissimo Ultra Tourbillon
Dial: Skeletonized
Lume: No
Case Material: Titanium
Case Dimensions: 40 mm Diameter, 1.85 mm thickness
Crystal: Sapphire glass
Case Back: Sapphire glass
Strap: Integrated titanium bracelet with folding clasp
Caliber: BVF 900
Dimensions: 1.50 mm thickness
Functions: Hours, minutes, 60-seconds tourbillon
Winding: Hand-wound
Frequency: 4 Hz (28,800 Vph)
Power Reserve: 42 Hours
Price: € 750,000 (steel)
Limited Edition: Yes, 20 pieces
