Watch reference library
Audemars Piguet Royal Oak Chronograph 26240ST
In production 2022 to present.
Specifications
- Case size
- 41mm
- Case material
- Stainless steel
- Bezel
- Octagonal stainless steel bezel secured by eight hexagonal screws
- Dial
- Grande Tapisserie pattern with two counters, offered in multiple colors, with a date window at 4:30
- Movement
- Calibre 4401, automatic, in-house, flyback chronograph
- Power reserve
- 70 hours
- Water resistance
- 50 meters
- Crystal
- Sapphire, with sapphire caseback
- Bracelet
- Integrated stainless steel bracelet with AP folding clasp
The story
Audemars Piguet discontinued its earlier 41mm Royal Oak Chronograph, reference 26331ST, in 2022 and replaced it with reference 26240ST, introduced in January 2022 alongside the Royal Oak's 50th anniversary. The 26240ST is the current reference for the 41mm steel Royal Oak Chronograph. The most significant change between the two references is mechanical. The 26331ST used the Calibre 2385, a movement built around a Frederic Piguet chronograph base with a column wheel, offering around 40 hours of power reserve. The 26240ST replaced it with the fully in-house Calibre 4401, which adds flyback functionality, allowing the chronograph to be reset and restarted in one motion, extends the power reserve to roughly 70 hours, and for the first time on this 41mm chronograph gives the watch a sapphire caseback so the movement can be viewed. Dial design also shifted with the changeover. The earlier 26331ST and its sibling 26239ST were sometimes fitted with contrasting counters for a panda-dial look, while the majority of 26240ST dials use a single, uniform color across the dial and counters. Early 26240ST watches from 2022 also included 50th Anniversary case back detailing, with standard production following from 2023 onward.
What to check before you buy
Buyers looking for a current-production 41mm Royal Oak Chronograph should specifically ask for the 26240ST and confirm the movement is the Calibre 4401, not the older Calibre 2385 used in the discontinued 26331ST, since the two look broadly similar but differ substantially in specification and price. A sapphire caseback is a quick way to distinguish the 26240ST, since the 26331ST used a solid steel caseback. As with other current Royal Oak chronographs, check bracelet condition, clasp function, and whether the piece includes its full box and papers. Flyback chronographs see more use of the pushers than standard chronographs in daily wear, so ask about service history.
Buying or selling a 26240ST?
Moda is always buying. Text photos to (605) 521-2821 for a fast offer, or start on the Moda Watches page. For any deal with a stranger, Moda's middleman service inspects the watch before money changes hands.
Common questions
Is 26331ST or 26240ST the correct current Royal Oak Chronograph 41mm reference?
26240ST is correct. Audemars Piguet discontinued the 26331ST in 2022 and replaced it with the 26240ST, which uses a different, newer movement.
What movement does the 26240ST use?
It uses the in-house Calibre 4401, an automatic flyback chronograph movement with a 70-hour power reserve, replacing the outsourced Calibre 2385 used in the 26331ST.
What does flyback mean on the 26240ST?
Flyback allows the chronograph to be stopped, reset, and restarted with a single push of the reset pusher, without needing to stop the chronograph first, which is useful for timing sequential events.
Does the 26240ST have a display caseback?
Yes. It has a sapphire caseback showing the Calibre 4401 movement, a feature the earlier 26331ST generation did not have.
What is the case size of the 26240ST?
41mm in stainless steel, the same case diameter as the 26331ST it replaced, though the case is slightly thicker to accommodate the new movement.