The Audemars Piguet Royal Oak 26735ST is the Royal Oak Selfwinding Flying Tourbillon Openworked in stainless steel: a 41 mm Royal Oak with the self-winding calibre 2972, a flying tourbillon at 6 o'clock and an openworked movement that serves as the dial. Audemars Piguet introduced it in 2022, the Royal Oak's 50th anniversary year, as the 26735ST.OO.1320ST.01 with the anniversary oscillating weight; the 26735ST.OO.1320ST.02 followed as the same complication with the standard rotor and a revised finish. It is a tourbillon, which is what separates it from the Double Balance Wheel Openworked 15407ST that shares its case size. This guide covers the specifications, what a flying tourbillon is, the two configurations, how the 26735ST compares with the 15407ST and the time-and-date 15510ST, how it wears, dated prices and what to check before buying. Bizak & Co. sources the 26735ST to order; the Royal Oak collection lists the configurations we can seek.
Last reviewed on October 4, 2026 by Filip Biczak. Prices are dated observations, not quotes.
Audemars Piguet Royal Oak 26735ST specifications
| Attribute | 26735ST |
|---|---|
| Case | 41 mm stainless steel, about 10.6 mm thick, satin-brushed with polished chamfers; screw-down crown |
| Bezel | Octagonal stainless steel with eight hexagonal white gold screws |
| Movement | Calibre 2972, self-winding, flying tourbillon at 6 o'clock, 3 Hz (21,600 vibrations per hour), about 65 hours of power reserve, hours and minutes, no date |
| Dial | Openworked: the movement is the dial, with the tourbillon cage visible at 6; applied white gold hour markers and Royal Oak hands with luminescent coating |
| Crystal | Glareproofed sapphire front and back |
| Bracelet | Integrated stainless steel bracelet with AP folding clasp |
| Water resistance | 50 m |
| Configurations | 26735ST.OO.1320ST.01 (2022, 50th anniversary oscillating weight) and 26735ST.OO.1320ST.02 (standard oscillating weight, revised finish) |
Source: Audemars Piguet, Royal Oak Selfwinding Flying Tourbillon Openworked 26735ST.OO.1320ST.01 and Audemars Piguet, Royal Oak Selfwinding Flying Tourbillon Openworked 26735ST.OO.1320ST.02; the AP watch collection page lists the current Royal Oak complications.
What is a flying tourbillon, and why does it matter here?
A tourbillon mounts the balance wheel, hairspring and escapement in a cage that rotates, usually once a minute, so that positional errors average out as the cage turns. A conventional tourbillon is held by a bridge above and a bearing below; a flying tourbillon is supported only from beneath, so there is nothing across the top of the cage and the whole mechanism is visible from the dial side. In the 26735ST the cage sits at 6 o'clock and is the first thing you notice: a small rotating assembly with the balance beating inside it, turning through a full circle each minute. The calibre 2972 is self-winding, which is less common for a tourbillon, so the watch winds on the wrist and does not need the daily hand-winding of older tourbillon calibres. The openworked construction exposes the barrel, the going train and the tourbillon in one view, and the finishing is done by hand to the standard Audemars Piguet applies to its complications.
26735ST.01 vs 26735ST.02: which one is the 50th anniversary?
The .01 is the anniversary configuration. Launched in 2022, it carries the "50 years" oscillating weight in 22 carat pink gold, the signature Audemars Piguet applied across the anniversary Royal Oaks that year, visible through the sapphire caseback. The .02 is the same flying tourbillon on the same calibre 2972 with the standard rotor and a revised treatment of the openworked movement, introduced after the anniversary year as the ongoing version of the model. From the front the two share the case, bezel, bracelet and tourbillon position; the finish of the bridges and the rotor are the differences. A quote for a "26735ST" should state the suffix, and the warranty card settles it. As with the other anniversary Royal Oaks, the .01 has a small following because the rotor was a one-year signature.
26735ST vs 15407ST: flying tourbillon or double balance wheel?
| 26735ST | 15407ST | |
|---|---|---|
| Complication | Flying tourbillon, openworked | Double balance wheel, openworked |
| Movement | Calibre 2972, 3 Hz, about 65 h | Calibre 3132, 3 Hz, about 45 h |
| Case | 41 mm steel, about 10.6 mm thick | 41 mm steel, about 9.9 mm thick |
| Seconds | None; the tourbillon cage marks the minute | Centre seconds |
| Years | 2022 to date | 2016 to date |
| Guide | This page | 15407ST guide |
| Bizak catalogue, 4 Oct 2026 | US$286,803 to 325,499, sourced to order | US$155,864 to 234,410, sourced to order |
Both are 41 mm steel Royal Oaks with openworked movements and both are often listed as "skeleton" Royal Oaks, which hides the difference. Look at 6 o'clock: the 26735ST has a rotating tourbillon cage; the 15407ST has two stacked balance wheels in a fixed position. The tourbillon is the more complex mechanism to build and finish, and it sits at roughly double the ask. The 15407ST guide covers the double balance wheel in detail.
26735ST vs 15510ST: tourbillon or time-and-date?
The 15510ST is the current 41 mm Royal Oak Selfwinding with a solid Grande Tapisserie dial, a date at 3 and the calibre 4302 with about 70 hours of reserve. It shares the 26735ST's case diameter, bezel and bracelet, and on the wrist the two have the same footprint. The 15510ST is the Royal Oak most people picture and the one with the deepest buyer pool; the 26735ST is a complication in the same case, made in far smaller numbers, without a date and with a movement you watch rather than a dial you read. If you want the Royal Oak look at the lowest entry in the current 41 mm, the 15510ST guide covers it; if you want the mechanism, this is the page.
How does the Royal Oak 26735ST wear?
At 41 mm and about 10.6 mm thick, the 26735ST is a little thicker than the time-and-date 15510ST and the double balance 15407ST, which the tourbillon cage accounts for, but it still sits low on the wrist because the integrated bracelet keeps the case close to the skin. Wrists above about 17 cm (6.7 inches) carry it well. Legibility is the trade-off of any openworked watch: the hands sit over a dense background of bridges and the cage, and reading the time takes a beat longer than on a solid dial. There is no seconds hand; the tourbillon cage completes one turn a minute and serves that purpose for anyone who wants to check the watch is running. The 65-hour reserve means it keeps going over a weekend off the wrist.
How much is a Royal Oak 26735ST? Retail and dealer prices in 2026
- Retail. Audemars Piguet publishes pricing on its product pages by market and allocates its tourbillons through its boutiques. The steel flying tourbillon has been the most expensive steel Royal Oak in the regular collection since it appeared; the AP pages linked above carry the current list figure for your market.
- Secondary market. In 2025 and 2026 the 26735ST has changed hands infrequently, and asks have varied widely with configuration, condition and set. The anniversary .01 has generally been asked above the .02 when both are new, though the pool of sellers is too small to call a settled gap.
- Bizak catalogue asks. On October 4, 2026 Bizak's sourced catalogue listed the 26735ST.OO.1320ST.01 at US$325,499 and the 26735ST.OO.1320ST.02 at US$286,803, both brand new and sourced to order. Those are two entries, not a market median, and the gap between them reflects what was obtainable on the day.
Ask for a dated quote for the exact suffix, year and set; our Audemars Piguet price guide explains how AP pricing is built and what moves it.
Is the 26735ST a good investment?
It is a watch to own rather than to trade. Steel Royal Oak complications are made in small numbers and have held value well, but a tourbillon at this price has a thin buyer pool and selling takes longer than selling a steel Selfwinding. A full set with the AP warranty card, the box and the removed links is the version that resells cleanly. Buy it for the mechanism; if resale speed matters, the 15510ST and 15407ST are easier to place.
Buying a 26735ST: what to check
- Full reference. Confirm 26735ST.OO.1320ST.01 or .02 on the warranty card and caseback. 15407ST is the double balance wheel without a tourbillon; 15510ST and 15400ST are time-and-date watches; 26735SG is the sand gold version and a different case metal.
- Tourbillon. The cage at 6 o'clock should rotate smoothly through a full turn each minute. Ask for a short video with the watch running; a listing that describes only an "openworked" or "skeleton" Royal Oak may be a 15407ST.
- Rotor. On the .01 the oscillating weight carries the "50 years" anniversary engraving; on the .02 it is the standard rotor. Ask for a caseback photograph.
- Case and bezel. The eight hexagonal screws should sit aligned; the brushed surfaces and polished chamfers should meet in sharp lines. Rounded edges mean polishing.
- Bracelet. Count the links and ask for the removed links. Check the clasp for play.
- Warranty. Every 26735ST is a 2022 or later watch, so it should be within AP's warranty period; the card, the box and the receipt should agree on the suffix and the dealer. The AP services page explains what the warranty and a full service cover.
- Price against the band. A steel flying tourbillon offered well below the asks above deserves a careful look at the seller before the watch.
Our authentication process describes what we inspect before dispatch, and the Royal Oak authentication guide covers the details that separate a correct Royal Oak from a worked-on one.
Quick answers
What is the Audemars Piguet Royal Oak 26735ST?
The Royal Oak Selfwinding Flying Tourbillon Openworked in stainless steel: a 41 mm Royal Oak with the self-winding calibre 2972, a flying tourbillon at 6 o'clock and an openworked movement in place of a dial, introduced in 2022.
Which 26735ST is the 50th anniversary edition?
The 26735ST.OO.1320ST.01, which carries the "50 years" anniversary oscillating weight. The 26735ST.OO.1320ST.02 is the same flying tourbillon with the standard rotor and a revised finish.
How much is a Royal Oak 26735ST?
Bizak's sourced catalogue listed the .01 at US$325,499 and the .02 at US$286,803 brand new on October 4, 2026, sourced to order. Retail is on the AP product pages by market.
What is the difference between the 26735ST and the 15407ST?
Both are 41 mm steel openworked Royal Oaks, but the 26735ST has a flying tourbillon with the calibre 2972 and the 15407ST has a double balance wheel with the calibre 3132. The tourbillon costs roughly double.
Does the 26735ST have a date or seconds hand?
No. It shows hours and minutes only; the tourbillon cage turns once a minute and serves as the running indicator.
Request a Royal Oak 26735ST sourcing quote
Tell us whether you want the .01 anniversary rotor or the .02, your preferred year, condition and whether a full set is required, plus your budget and timing, through our sourcing enquiry form. We confirm the specific watch, photographs, card and final price before you commit. Catalogue entries: 26735ST.OO.1320ST.01 and 26735ST.OO.1320ST.02; browse the Royal Oak collection, the watches over US$50,000 collection, or sell or trade your Royal Oak.
Related reading: Royal Oak 15407ST double balance wheel guide · Royal Oak 15510ST guide · Royal Oak 15400ST guide · Audemars Piguet price guide.
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