Description
Audemars Piguet Royal Oak Perpetual Calendar Blue 26574ST
The Audemars Piguet Royal Oak Perpetual Calendar 26574ST is a 41mm stainless-steel Royal Oak that combines the collection’s distinctive octagonal architecture with one of watchmaking’s most useful calendar complications. The blue configuration is particularly recognizable for its Grande Tapisserie dial, contrasting blue subdials and integrated stainless-steel bracelet. Reference 26574ST.OO.1220ST.02 was introduced in 2015, while the .03 configuration followed in 2021 with a slightly different shade of blue.
What Makes the 26574ST Perpetual Calendar Special?
Unlike a standard date watch, a perpetual calendar tracks several calendar indications mechanically. The 26574ST displays the date, day, month, week number, leap year and moon phase while accounting for the different lengths of months and leap years.
This makes the watch considerably more complicated than a conventional three-hand Royal Oak. The information is distributed across multiple subdials, creating a balanced but detailed dial layout.
41mm Stainless-Steel Case
The Royal Oak Perpetual Calendar 26574ST uses a 41mm stainless-steel case measuring approximately 9.5mm thick. Its proportions give the watch a larger presence than earlier smaller Royal Oak perpetual-calendar models while maintaining a relatively thin profile for such a complicated mechanical watch.
The familiar octagonal bezel and exposed screws remain central to the design. Brushed and polished finishing across the case and bracelet creates contrast and emphasizes the sharp geometry that defines the Royal Oak collection.The watch is rated to approximately 20 metres of water resistance, with sapphire crystal used on the front and caseback.
Blue Grande Tapisserie Dial
The blue dial is one of the most recognizable features of this configuration. It uses the Grande Tapisserie pattern, while the smaller calendar displays and inner bezel use contrasting blue shades.
The 2021 26574ST.OO.1220ST.03 introduced a slightly different blue tone compared with the earlier .02 configuration. Audemars Piguet describes the dial using its characteristic “Night Blue, Cloud 50” color treatment for the subdials and inner bezel.White-gold applied hour markers and Royal Oak hands use luminescent material, helping maintain readability despite the number of indications displayed across the dial.
Automatic Calibre 5134
Inside the 26574ST is automatic Calibre 5134, an extra-thin perpetual-calendar movement. The calibre measures approximately 4.3mm thick and provides around 40 hours of power reserve. It contains 38 jewels and operates at 2.75Hz.
The movement handles the watch’s hours and minutes alongside the perpetual-calendar functions. These include date, day, month, leap year, week number and astronomical moon-phase indications.The sapphire caseback also provides a view of the movement’s finishing, including its decorated surfaces and openworked 22-carat gold oscillating weight.
Perpetual Calendar Functions Explained
The defining feature of this Royal Oak is its ability to display multiple calendar measurements from one mechanical system.The watch indicates the day of the week, date, month, week number and leap-year cycle, while the moon-phase display provides an astronomical indication. Because these functions are mechanically linked, the perpetual-calendar mechanism is designed to account for variations in month length and leap years.
This complication is what separates the 26574ST from simpler Royal Oak models that only provide a standard date display.
26574ST Specifications
| Specification | Details |
| Collection | Royal Oak |
| Model | Perpetual Calendar |
| Reference | 26574ST |
| Case diameter | 41mm |
| Case material | Stainless steel |
| Thickness | 9.5mm |
| Dial | Blue Grande Tapisserie |
| Movement | Automatic |
| Calibre | 5134 |
| Power reserve | Approximately 40 hours |
| Jewels | 38 |
| Functions | Date, day, month, week, leap year, moon phase |
| Bracelet | Stainless steel |
| Crystal | Sapphire |
| Water resistance | 20m |
Specifications are based on manufacturer and reference-database information for the blue 26574ST configurations.
26574ST.02 vs 26574ST.03
This distinction is important when researching the blue Royal Oak Perpetual Calendar 26574ST.
The 26574ST.OO.1220ST.02 was introduced in 2015 and uses the earlier blue-dial configuration. The 26574ST.OO.1220ST.03 arrived in 2021 as its replacement and features a slightly different blue shade. The basic case dimensions, stainless-steel construction and Calibre 5134 remain closely related.
Therefore, if you’re comparing listings, always check the full reference suffix rather than relying only on “26574ST blue.”
Why Collectors Pay Attention to This Reference
The 26574ST is interesting because it brings together three important Royal Oak characteristics: the integrated bracelet, recognizable octagonal case and a highly complicated mechanical movement.
Its 41mm proportions also make it a modern interpretation of the Royal Oak Perpetual Calendar, while the blue Grande Tapisserie dial gives the watch a strong visual identity.The reference is now part of the secondary market, with WatchCharts identifying the 26574ST variations as discontinued models.
FAQs
What is the Audemars Piguet 26574ST?
The 26574ST is a 41mm stainless-steel Royal Oak Perpetual Calendar with automatic Calibre 5134 and multiple calendar indications, including date, day, month, week, leap year and moon phase.
What movement does the 26574ST use?
It uses Audemars Piguet Calibre 5134, an automatic perpetual-calendar movement with approximately 40 hours of power reserve and 38 jewels.
What size is the Royal Oak Perpetual Calendar 26574ST?
The case measures 41mm in diameter and approximately 9.5mm in thickness.
Does the 26574ST show the moon phase?
Yes. The perpetual-calendar mechanism includes an astronomical moon-phase indication, along with date, day, month, week number and leap-year information.
What is the difference between 26574ST.02 and 26574ST.03?
Both are blue-dial 41mm stainless-steel Royal Oak Perpetual Calendar references using Calibre 5134. The .03 was introduced in 2021 and has a slightly different blue shade from the earlier .02 configuration.
