With the RM 21-01, Richard Mille presents a new case design. The complex structure of the case in 5N red gold is reinforced with an exoskeleton in Carbon TPT®, used for the bezel and pillars. This extremely light and durable composite is made by stacking hundreds of layers of carbon fibres thanks to an automated process that rotates 45° between each layer, then heated to 120° in an autoclave before being machined to the nearest micron. Carbon TPT® is found at the heart of the baseplate, this time combined with an orthorhombic honeycomb structure embodying the concept of air itself and made of HAYNES® 214® with a blue PVD treatment, a first for the brand. This nickel-chromium-aluminium-iron alloy is primarily intended for use in thermal environments exceeding 955°. Optimal resistance to high-temperature oxidation makes this material—which can nonetheless be moulded and assembled by conventional methods—an especially suitable choice for combustion chambers. Consequently, the RM 21-01’s baseplate offers unsurpassed stiffness, an extremely low thermal expansion coefficient and exceptional torque resistance.
For the bridges, Richard Mille’s movements team opted for grade 5 titanium, a biocompatible titanium-aluminium-vanadium alloy used in the aerospace industry that ensures superior rigidity and excellent corrosion resistance. The barrel and tourbillon bridges, consisting of four arms on an openwork circular base edged in gold, are seated in the central crucible of the plate lending them mechanical properties ideally suited to the rotation of these moving parts, while allowing the beauty of the tourbillon to shine through. This calibre is finished with a PVD treatment in 5N red gold to enhance the contrasts created by the case and the character of this flightworthy mechanism.
The sapphire glass dial provides a flawlessly transparent window into the manual-winding Calibre RM21-01. The power-reserve indicator is placed in lieu of the number at 11 o’clock, while the torque indicator occupies the 1 o’clock position. The latter makes it possible to immediately know the barrel spring’s tension and thus optimise the movement’s functioning. At 4 o’clock sits the function selector, operated by a pusher integrated into the centre of the crown, which is crafted in Carbon TPT® and 5N red gold with a gasket in the same material as the white rubber bracelet. A simple press suffices to switch from the Neutral (N) position to Winding (W) to Hand-Setting (H).