World’s Thinnest Mechanical Watch: The Piaget Altiplano Ultimate Concept You Can Now Own

Piaget gave us a glimpse of the Altiplano Ultimate Concept in 2018 during the brand’s 60th-anniversary celebrations of the Altiplano collection. The watch, a prototype only, was an experiment in micro-engineering. Piaget has always called itself the master of thin watches — the brand debuted its first extra-thin movement, the 9P in 1957 and went on to hold the world record of the thinnest mechanical watch in 2014 with the launch of the Altiplano 900P that was just 3.65mm thick.

The prototype of the Altiplano Ultimate Concept in 2018 met with widespread interest. A gossamer thinness of 2mm only, the hand-wound watch stood at the same size as the Calibre 9P, or about the same thickness of a 1 Euro coin.

It may have begun as an experiment in micro-engineering, but now, two years later, the Altiplano Ultimate Concept is finally a fully developed, tried-and-tested watch that is customisable and available to clients as a special-order piece.

The new Altiplano Ultimate Concept features the same base construction as the 900P to achieve ultra-thinness — one of Piaget’s historical innovations was to take the standard four-layer movement construction and fuse it together. The miniaturisation process thus begins with removing the movement baseplate and machining the movement directly onto the caseback. The new watch additionally comes with five patents, there is no doubt that this watch is a real technical feat.

Piaget Altiplano Ultimate Concept
A New Movement Construct

The watch is too thin to be cased in gold, which is too soft. Instead, a new cobalt-based alloy is used. Highly resistant, the cobalt alloy is 2.3 times stronger than gold and therefore that much harder to machine as well. Every part of the watch had to be rethought, utilising new ways of watchmaking to keep the watch at 2mm thick. The wheels are reduced from a conventional 0.2mm thick to 0.12mm, and the sapphire crystal, typically at 1mm thick, is reduced to 0.2mm only. Even the way the crystal is attached to the case had to be specially worked out.

Time is told on an off-centre sub-dial, allowing the rest of the movement to be laid out flat, thus minimising thickness. This also means the entire construction of the movement is out in the open for all to see.

Piaget Altiplano Ultimate Concept

At 9 o’clock, the balance wheel and the hairspring on the Altiplano Ultimate Concept had to be completely rethought as a ball-bearing mechanism. The balance-wheel bridge, typically the tallest component in a movement, is now completely removed. The balance-staff, the inner ring of the ball-bearing mechanism and the roller now form an indivisible whole. This novel construction means that the conventional set-up is now inverted so that the hairspring sits under the balance wheel. A free-sprung balance is used instead, which is compensated by four adjustable weights.

The mainspring barrel, at 6 o’clock, is also entirely reimagined, the design now has no cover or drum but is mounted on a single, ceramic ball-bearing within the frame of the watch, and transmits energy via the latter’s inner ring, commanding a decent 40 hours of power reserve.

The crown is also a complete redesign. Taking the form of a flat, telescopic system, that comes with its own specially-designed winding tool the crown sits flush with the case band to maintain that streamlined look. It also serves more than just an aesthetic function to protect the crown from unwanted impact. Sacrificing the more bulky sliding pinion and crown wheel, the watch uses a single “infinite screw” instead, or in other words, a worm gear.

Hand-wound Calibre 900P-UC
Hand-wound Calibre 900P-UC
Bespoke Options

Thin the watch might be, but the finishing is still top-notch. The movement is embellished with sunburst and satin-brushed finishes, chamfered and polished bridges and the case/baseplate of the watch is even enhanced with PVD treatment. The creativity does not stop there.

The Altiplano Ultimate Concept is extensively customisable and made to order for Piaget’s discerning clients. Buyers may specify the colour of the bridge and dial, the finish of the hands and the main plate, and select straps that they prefer. Only one thing is non-negotiable, and that is the case material, which due to the thinness of the watch, is required to be the cobalt-based alloy.

Technical Specifications


Hand-wound Calibre 900P-UC, hours, minutes off-set at 12 o’clock, power reserve of 40 hours


41mm diameter, 2mm height, cobalt alloy


Alligator leather and Kevlar strap with ultra-thin pin buckle

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