- Case
- Round, four parts, chamfered, polished and brushed
- Movement
- Manual winding
- Size
- 50.00 × 13.90 mm
- Edition
- 10 pieces
Overview
AP direct-impulse escapement at 36,000 vph in an ARCAP calibre
Introduced in 2012 as a limited edition of ten pieces, the RM 031 was built around a single specification: a rate variation of less than 30 seconds per month. The calibre RM031 is manually wound and shows hours, minutes, small seconds and a function indicator.
Its escapement is the AP direct-impulse type developed by APR&P for Audemars Piguet, a combination of detent and Swiss lever principles in which the escape wheel acts directly on the balance. The round case measures 50.00 × 13.90 mm and is made in four parts, chamfered, polished and brushed, with lugs shaped to extend the case lines into the curve of the strap.
Key details
Edition10 pieces, 2012
EscapementAP direct-impulse, 36,000 vph (5 Hz)
Rate specificationVariation of less than 30 seconds per month
Design and engineering
- AP direct-impulse escapementDeveloped by APR&P for Audemars Piguet, it combines detent and Swiss lever principles. The escape wheel acts directly on the balance rather than through the pallet fork acting on the escape wheel, and a purpose-designed dart prevents overbanking.
- Twin opposed balance springsThe escapement runs at 36,000 vibrations per hour with two elinvar balance springs set in opposite directions.
- ARCAP baseplate and bridgesARCAP was first used in watchmaking in the Richard Mille calibre RM002. It is corrosion-resistant and antimagnetic. Finishing includes a microblasted baseplate and escapement holder, polished, microblasted, bevelled and circular-grained wheels, burnished sections and soft-polished escapement bridges.
- Double barrel and 20° pressure anglePower from the twin barrels is transmitted through a going train whose teeth are profiled to a 20° pressure angle, a specification drawn from automotive transmissions.
- Four-part round case50.00 × 13.90 mm, chamfered, polished and brushed. The casing ring is eliminated and the movement is fixed to the chassis by three grade 5 titanium screws and silicon blocks (ISO SW).
Specifications
Technical specifications
| Reference | RM 031 |
|---|---|
| Calibre | RM031 |
| Movement | Manual winding |
| Functions | Hours, minutes, small seconds, function indicator |
| Rate specification | Variation of less than 30 seconds per month |
| Movement dimensions | 36.00 mm diameter, thickness 6.35 mm |
| Jewels | 26, set in white gold chatons |
| Balance | CuBe, 4 arms, 4 regulating screws, moment of inertia 10 mg·cm², angle of lift 50° |
| Frequency | 36,000 vph (5 Hz) |
| Balance spring | Opposed elinvar double balance spring |
| Escapement | AP direct-impulse |
| Shock protection | Incabloc 908.22.211.100 (transparent) |
| Baseplate and bridges | ARCAP |
| Barrels | Double barrel |
| Going train | 20° pressure angle on the teeth |
| Movement mounting | Three grade 5 titanium screws and silicon blocks (ISO SW); no casing ring |
| Case | Round, four parts, chamfered, polished and brushed |
| Case dimensions | 50.00 × 13.90 mm |
| Strap | Black rubber |
| Introduced | 2012 |
| Edition | 10 pieces |
Buying with HYPA
Purchase with confidence
- Manufacturer warranty confirmed from the warranty card
- Insured worldwide delivery
- Payment by bank transfer or cryptocurrency
- Registered Australian dealerHYPA International Pty Ltd · Victorian Second-Hand Dealer Licence SHD-0018017.
- Direct specialist supportSpeak with the HYPA team before, during and after the purchase.
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