The Audemars Piguet Royal Oak 15500ST.OO.1220ST.02 is the standard 41 mm self-winding Royal Oak: a stainless-steel case with the octagonal bezel and integrated bracelet Gérald Genta drew in 1971, a slate-grey Grande Tapisserie dial, and the in-house calibre 4302 with a central seconds hand and a date window. Introduced in 2019, it replaced the 15400ST and remains, alongside its 2022 update the 15510ST, the entry point into the current Royal Oak line. This guide covers the specifications, what changed from the 15400ST it replaced, how it compares with the newer 15510ST, how the watch wears, price context in 2026 and what to check before buying. Bizak & Co. sources the 15500ST to order; the Royal Oak collection lists the configurations we can seek.
Last reviewed on September 27, 2026 by Filip Biczak. Prices are dated observations, not quotes.
Audemars Piguet Royal Oak 15500ST.OO.1220ST.02 specifications
| Attribute | 15500ST.OO.1220ST.02 |
|---|---|
| Case | 41 mm stainless steel, about 10.4 mm thick, octagonal bezel with eight hexagonal screws |
| Movement | Calibre 4302, automatic, 70 hours power reserve, hacking seconds, instantaneous quickset date |
| Dial | Slate-grey Grande Tapisserie, central seconds, date at 3 o'clock |
| Crystal | Sapphire, with a sapphire exhibition case back |
| Bracelet | Integrated stainless steel with AP's folding clasp |
| Water resistance | 50 m nominal rating |
| Predecessor | 15400ST (2012 to 2019) |
Source: Audemars Piguet, Royal Oak collection page.
What changed from the 15400ST?
The 15500ST replaced the 15400ST in 2019 with a new in-house movement rather than a new case shape. The 15400ST ran calibre 3120, a 3 Hz automatic with about 60 hours of power reserve; the 15500ST's calibre 4302 runs at 4 Hz with 70 hours of reserve and adds hacking seconds and an instantaneous quickset date, neither of which the 3120 had. The case kept the same 41 mm diameter and the same eight-screw octagonal bezel that has identified every Royal Oak since 1972, though the case grew marginally thicker to accommodate the larger calibre. The Grande Tapisserie dial pattern, the integrated bracelet and the folding clasp carried over largely unchanged. The 15500ST is also produced with blue and black Grande Tapisserie dials in the same 41 mm case, each under its own reference suffix; the slate-grey dial reviewed here is one of three colours in the current line.
15500ST vs 15510ST: which Royal Oak?
| 15500ST | 15510ST | |
|---|---|---|
| Dial pattern | Grande Tapisserie, smaller waffle squares | Mega Tapisserie, larger waffle squares |
| Movement | Calibre 4302, 70 h reserve | Calibre 4302, 70 h reserve |
| Case | 41 mm steel | 41 mm steel, unchanged |
| Introduced | 2019 | 2022 |
| Bizak catalogue, 27 Sep 2026 | US$46,350 new; US$42,189 pre-owned | US$54,223 new |
The 2022 update changed the dial's waffle pattern and, on some dial colours, its finishing; the case, movement and bracelet are the same calibre 4302 platform as the 15500ST. Buyers who want the current Grande Tapisserie look the 15500ST has carried since 2019 should note that it is the earlier of the two, not a discontinued or lesser version; both use the same movement and are current or recently current production depending on dial and market. Our 15500ST vs 15510ST comparison also sets both against the 15400ST.
How does the Royal Oak 41mm wear?
The octagonal bezel and integrated bracelet were designed to look like a single continuous object rather than a case with a strap attached, and at 41 mm with a thickness of about 10.4 mm the watch sits close to the wrist despite the bracelet's width. The case has no conventional lugs, so the bracelet's first links do the work lugs would normally do, and a well-fitted bracelet with the correct number of links is central to how the watch sits; a Royal Oak with too many or too few links looks and wears differently from one properly sized. Because the bezel screws align by design rather than by chance, cases are finished and re-finished by hand to keep that alignment, which is one reason a well-preserved, unpolished example is valued over one that has been to a jeweller for a quick buff.
Why does the Royal Oak still define AP's steel sports watch?
Gérald Genta designed the first Royal Oak, reference 5402, for Audemars Piguet in 1971 and it reached the market in 1972 as a steel watch priced like a gold one, an idea that struck most of the industry as a mistake at the time. The octagonal bezel, the exposed hexagonal screws and the integrated bracelet were unlike anything else in fine watchmaking, and the design has been in continuous production since, longer than any other luxury sports watch of its kind. The 15500ST carries that design forward largely unaltered: the bezel geometry, the "Tapisserie" dial pattern (a waffle-like guilloché first used on the 5402) and the bracelet's tapering links all trace directly back to the original. What has changed across five decades is size, materials and the movement inside the case, not the silhouette.
That continuity is a large part of why the 15500ST, despite being the most produced current Royal Oak reference, still commands a genuine following rather than being seen as a generic steel sports watch. Buyers are not simply choosing a case shape; they are buying into a design that has survived largely unchanged since Nixon was in office, built to a specific and demanding finishing standard that AP applies across the range regardless of reference.
How much is an Audemars Piguet Royal Oak 15500ST? Price context in 2026
- Retail. Audemars Piguet's list prices are confirmed at its boutiques and authorised dealers and have moved higher across the Royal Oak range since the 15500ST's 2019 launch; the AP's current list for the steel 41 mm three-hand model is on the collection page linked above.
- Secondary market. Steel Royal Oak models with wide production, like the 15500ST, generally trade closer to retail than the brand's more limited references, though allocation at retail remains difficult for new clients at many dealers.
- Bizak catalogue asks. On 27 September 2026 our sourced catalogue listed the slate-grey 15500ST.OO.1220ST.02 at US$46,350 brand new, a pre-owned grey-dial 15500ST at US$42,189, and the newer 15510ST.OO.1320ST.10 at US$54,223 brand new, all sourced to order.
Those figures describe what we saw and will move. Ask for a dated quote for the exact dial, year and set; our Audemars Piguet price guide explains how to compare quotes.
Is the Royal Oak 15500ST a good investment?
Treat it as a watch to wear rather than a short-term trade. The wide production run of the 15500ST means it does not carry the scarcity premium of a limited Royal Oak Offshore or an early Jumbo, and secondary asks track retail more closely than the most hyped references in the family. What holds value within the reference is condition: an unpolished case with sharp bezel edges, a complete set of links, and original box and papers. Buy it because the design and the movement upgrade over the 15400ST are what you want; if resale matters, ask for a written cash-buy assessment before you commit.
Buying a used 15500ST: what to check
- Warranty card and papers. The warranty card serial should match the case back, and AP does not reissue lost cards; ask whether the five-year warranty is still active.
- Bezel and case. The eight hexagonal screws should sit flush and aligned; sharp transitions between the brushed top and polished sides of the case are original, and rounded edges indicate polishing.
- Bracelet fit and links. Count the links and check for stretch at the clasp; an integrated bracelet that has been shortened incorrectly changes how the watch sits.
- Dial and date. The Grande Tapisserie pattern should be crisp with no fading between squares; confirm the date changes instantaneously at midnight, a feature of the calibre 4302 that the older 3120 lacked.
- Movement and service. Ask for the last service date; a calibre 4302 running well outside its rated accuracy may be due a service. Audemars Piguet's services page describes its authorised network.
- Price against the market. A full-set 15500ST offered well under the going range is the single most reliable warning sign.
Our authentication process describes what we inspect before dispatch.
Quick answers
How much is an Audemars Piguet Royal Oak 15500ST?
Bizak's sourced catalogue listed the slate-grey 15500ST.OO.1220ST.02 at US$46,350 brand new and a pre-owned example at US$42,189, sourced to order on 27 September 2026.
What is the difference between the 15400ST and 15500ST?
The 15500ST replaced the 15400ST's calibre 3120 (60 hours, 3 Hz) with the calibre 4302 (70 hours, 4 Hz), which added hacking seconds and an instantaneous quickset date. The case size and bezel design stayed the same.
Is the 15500ST the same as the 15510ST?
No. Both use the calibre 4302, but the 15510ST, introduced in 2022, carries a larger Mega Tapisserie dial pattern in place of the 15500ST's Grande Tapisserie.
What size is the Royal Oak 15500ST?
41 mm across and about 10.4 mm thick, with a 50 m water-resistance rating.
Does the Royal Oak 15500ST have a date function that sets instantly?
Yes. The calibre 4302 sets the date instantaneously at midnight, unlike the earlier calibre 3120 used in the 15400ST.
Request a Royal Oak 15500ST sourcing quote
Tell us the dial colour, preferred year, condition and whether the warranty card 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: 15500ST.OO.1220ST.02 slate grey, 15500ST.OO.1220ST.03, pre-owned 15500ST grey, 15510ST.OO.1320ST.10; browse the Royal Oak collection, or sell or trade your Royal Oak.
Related reading: Audemars Piguet price guide · Richard Mille RM 17-02 guide · Rolex Submariner 126610LN guide · Authenticity guarantee.
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