Two years after it showcased a concept Altiplano at the 2018 Salon International de la Haute Horlogerie (SIHH), Piaget has now unveiled the thinnest mechanical watch in the world, the Atiplano Ultimate Concept measuring an incredibly 2 mm only, that’s the thickness of a 1 Euro coin.

It’s going to take some doing to steal this world record from Piaget but Bulgari, no doubt, will be watching. The Italian brand pretty much owns every ultra-thin record in watchmaking today. The Altiplano Ultimate Concept is unique in the sense that the case forms part of the movement. It also features a new gear train construction for optimum energy regulation and an integrated winding crown.
And while Bulgari may have the records now, it is Piaget that is historically associated with ultra-thin movements in the industry. In 1957, it gave us the manual-winding 9P Caliber, measuring just 2 mm thick. This was the world’s thinnest mechanical watch in 1957. They’ve done well to create an entire case that’s the same thickness as that 1957 movement. Just how this go about this delicate task?

For starters, they had to rethink watch design. Classical design dictates a standard four-tier construction: bezel and crystal; dial, hands and movement placed in a case and fitted with a caseback. Piaget’s engineers had to draw from the learnings in creating the Altipano 900P in 2014, wherein the caseback also served as a bottom plate for the movement. At 3.65 mm, the Altiplano 900P also held the title of the world's thinnest mechanical watch at that time.
So out went the traditional mainplate that’s a feature of conventional movements. The caseback now does double duty – as the back of the case and movement mainplate. The engineers had to turn to a new cobalt-based alloy to machine the mainplate, as gold would have too difficult (and delicate) to machine at this level of tolerances.
The caseback now does double duty – as the back of the case and movement mainplate.
The wheels of the gear train were re-engineered and reduced from a conventional 0.20 mm thick to 0.12 mm, the sapphire crystal which is normally 1 mm thick in a standard watch, is just 0.2 mm thick here. The mainspring barrel has also been entirely redesigned. The barrel has no cover now and is mounted on a single, ceramic ball-bearing within the frame of the watch. The crown, meanwhile, has been re-invented to take the form of a flat, telescopic system (with its own, specially-designed winding tool) that fits flush with the case band and in which the conventional sliding pinion clutch and crown wheel are substituted for a single, 'infinite screw'. This not only protects the crown but also shields the movement from unwanted shock.

The method of indicating the time had to be reimagined too. Instead of having a dial and two hands placed on top of a bridge, the Altiplano Ultimate Concept features a dial that lies beneath it, thus providing protection from any contact with the strong but wafer-thin crystal should it be momentarily deformed in an impact. A conventional, straight winding stem could not be used here because of the off-center dial. So Piaget created a patented 'staggered' stem. In order for the system to function perfectly, the conventional hour hand is replaced with a revolving indicator disc while the minute hand works in the usual way. The watch has a power reserve of 40 hours and an escapement that beats at 4Hz (28,800 vph).
In an unusual move, the dial is placed beneath the movement bridge to protect it further.
The hand-decorated movement Caliber 900P-UC is made up of 167 individual parts, which was again a challenge because some of these parts were incredibly tiny. Nevertheless, the movement is decorated with sunburst and satin-brushed finishes, chamfered and polished bridges abound. The watch is paired with either an alligator skin strap or a blue textile strap with an ultra-thin cobalt pin buckle. The Altiplano Ultimate Concept is customizable, so customers have the opportunity to completely own their timepiece. Though this is not a limited edition timepiece, production will be limited owing to the complicated nature of the construction. The price is not available yet but we will update the story once we know more details.