RM 028 AUTOMATIC
AUTOMATIC WINDING DIVER'S WATCH
DEVELOPMENT GUIDED BY EXTREME SUBMARINE CONDITIONS
Following the direction set out by the first diver’s watch created by Richard Mille, the RM 025, the RM 028 uses a number of key elements that demarcate the theme of diving within the collection. Its exceptional tripartite case with a unidirectional bezel and water resistance to 300 metres follows ISO diver’s watch norm 6425, creating a perfect environment to house the skeletonised movement with variable rotor geometry, a Richard Mille exclusive.
Automatic winding movement with hours, minutes, central seconds, date and variable-geometry rotor.
BASEPLATE AND BRIDGES MADE OF GRADE 5 TITANIUM
The baseplate and bridges were subjected to separate and extensive validation tests to ensure it met optimal strength requirements.
• Arm in grade 5 titanium
• High palladium content 18K white gold weight segments
• Weight segment with 6 possible positions adjusted by screws in grade 5 titanium
• Ceramic ball bearings
• Unidirectional; anti-clockwise winding direction.
Thickness: 4.14 mm
Number of jewels: 32
Barrel arbour: AP 20 steel
Balance: Glucydur®, 4 arms, moment of inertia 4.8 mg•cm2, angle of lift 53°
Frequency: 28,800 vph (4 Hz)
Balance spring: elinvar by Nivarox®
Shock protection: INCABLOC 908.22.211.100 (transparent)
Escapement wheel jewels: Rubifix (transparent)
Three-position stem: manual winding, date adjustment, time setting
This is achieved with a unique, curved, tripartite case design using torque screws that can be individually and precisely tensioned with high accuracy around the exterior circumference of the case. This is complemented by a screw-lock crown construction.
The use of an additional screwed system attaching the bezel to the watchcase makes it absolutely stable, as well as impossible to inadvertently dislocate or loosen. In addition, the use of screws makes perfect adjustment possible, since the bezel is not tensioned into position.
For clearer visibility under murky conditions, starting at 12 o’clock, the five-minute markers of the first quarter are highlighted in red.
• Burnished pivots
• Diamond-polished sinks on the bridge side
• Pinions with undercuts
• Anglage and polishing by hand
• Screw slot and screws bevelled and polished with rounded and polished tip
• Minimal corrections applied to the wheels in order to preserve geometry and performance
FREE-SPRUNG BALANCE WITH VARIABLE INERTIA
SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
This permits better control of the torque applied to the screws during assembly. These screws are unaffected by physical manipulation during assembly or disassembly and age well.