GrailAtlasAn independent reference for mechanical watches
Audemars Piguet

AP 3120

Swiss lever · introduced 2003
Beat rate
21,600 vph
Power reserve
60h
Jewels
38
Introduced
2003
Escapement
Swiss lever

The AP 3120 is the manufacture automatic at the core of the Royal Oak, developed in-house by Audemars Piguet as a replacement for the JLC 2121. Côtes de Genève, beveling, perlage, and anglage are applied by hand to all visible surfaces. The 22-carat gold rotor is standard. Collectors who open the caseback of a Royal Oak cite this movement as a central part of the ownership experience.

Specifications

Beats per hour
21,600
Jewels
38
Power reserve
60h
Diameter
26.6mm
Height
4.26mm
Escapement
Swiss lever
Introduced
2003
Finishing
Haute horlogerie
Service interval
8 years
Service cost tier
Haute

Complications

dateweekday

Known service issues

  • Fine hand-finishing means service requires AP-trained watchmakers to preserve the anglage and surface work; generic service destroys resale value
  • Date corrector lever spring is a known wear point after 15-plus years

Notable in

  • Audemars Piguet Royal Oak 15400ST
  • Audemars Piguet Royal Oak 15202ST (Ultra-Thin, 2121)
  • Audemars Piguet Royal Oak Offshore 25721ST

References in our catalog using this caliber

Buying advice

Practical guides for buying a watch with this caliber on the pre-owned market:

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AP 3120 | movement specs | Grail Atlas