If you have ever owned an Audemars Piguet Royal Oak — or spent time around someone who has — you are likely familiar with its most defining feature: the bezel. Precisely machined, geometrically perfect, and instantly recognizable, the Royal Oak bezel has been a cornerstone of Gérald Genta’s design since 1972.
That same precision, however, comes with a drawback. The Royal Oak bezel is notoriously unforgiving when it comes to wear. Even the smallest scratch or nick is immediately visible, with no place to hide imperfections on its crisp, flat surfaces.
Preserving Geometric Integrity
Unlike watches that gain charm through patina and visible wear, the Royal Oak bezel demands a different mindset. Its sharply defined edges and brushed surfaces amplify even the slightest damage, forcing owners to accept wear as part of ownership — or to handle the watch with extreme care.
Vintage Audemars Piguet collectors are especially sensitive to this issue. Over-polishing a Royal Oak bezel can permanently compromise its geometry, softening edges and altering proportions that were originally executed with extraordinary precision. Once that geometry is lost, it cannot be restored.
This challenge led Audemars Piguet to explore alternative materials capable of preserving the Royal Oak’s defining lines without sacrificing wearability.
Introducing Bulk Metallic Glass (BMG)
To address this long-standing issue, Audemars Piguet introduced a material with a deceptively simple name: bulk metallic glass, commonly referred to as BMG.
Despite the term “glass,” BMG is not fragile or brittle like conventional silica glass. Instead, it is a metal alloy that lacks a traditional crystalline structure. This amorphous internal structure gives BMG exceptional hardness and scratch resistance — properties highly desirable for protecting the Royal Oak’s iconic bezel.
Heart of Glass, Harder Than Stone
Most metal alloys consist of repeating crystal structures formed during cooling. The size and arrangement of these crystals play a major role in a material’s mechanical properties. When an alloy cools slowly, crystals grow larger. When it cools rapidly, crystals remain small — or fail to form altogether.
In the case of bulk metallic glass, the cooling process is so rapid that crystals never develop. The result is a material with a glass-like internal structure that offers significantly higher hardness than conventional watchmaking metals.
Unlike traditional glass, however, metallic glass combines this hardness with toughness, making it far more resistant to scratches and deformation.
Celestial and Historical Inspiration
The concept of crystal formation through cooling is not new to watchmaking. One of the most dramatic examples of crystal growth can be found in iron-nickel meteorites, which cool over millions of years in space. This slow cooling creates the Widmanstätten patterns seen on meteorite watch dials.
Conversely, rapid cooling — as used in metallic glass — produces the opposite effect: no crystals at all. This principle has inspired not only case materials, but also dial manufacturing techniques across high-end watchmaking.
BMG represents the extreme end of this metallurgical spectrum.
A Milestone Moment for the Royal Oak
Audemars Piguet first showcased the potential of BMG during the Only Watch 2021 charity auction, presenting the final classic Royal Oak Jumbo reference 15202 featuring the historic caliber 2121, paired with a BMG bezel and caseback. That watch sold for an extraordinary CHF 3.1 million, highlighting both the material’s technical significance and its collectability.
Following this milestone, BMG became a defining feature of select modern Royal Oak Jumbo references, particularly those celebrating the model’s 50th anniversary.
Modern Watchmaking Problems, Modern Solutions
While many enthusiasts remain nostalgic for the legendary caliber 2121 — a movement revered for its thinness and beauty since 1967 — practical realities eventually necessitated change. The 2121’s production complexity, servicing challenges, and lack of a quickset date made it less suitable for modern expectations.
Enter the new caliber 7121. Designed without increasing case thickness, the 7121 offers improved reliability, efficiency, and usability while preserving the slim profile that defines the Royal Oak Jumbo.
This transition reflects a broader truth in modern watchmaking: heritage must coexist with progress.
A Glimpse Into the Future of the Royal Oak
Alongside technical innovation, Audemars Piguet continues to refine the Royal Oak’s aesthetic appeal. Anniversary models introduced striking fumé dials, including deep burgundy, rich gradients, and classic tapisserie textures that pay homage to the past while embracing modern tastes.
The integration of BMG into the bezel and caseback protects these visual elements by preserving the watch’s sharp geometry over time. While challenging to manufacture due to strict cooling requirements, BMG’s material properties make it uniquely suited to safeguarding one of watchmaking’s most enduring designs.
The Royal Oak Jumbo in BMG and Titanium
The Royal Oak Jumbo in BMG and titanium measures 39mm in diameter and features a BMG bezel and caseback paired with a lightweight titanium case. Sapphire crystals with anti-reflective coating protect both sides of the watch.
The smoked burgundy dial is accented with 18k pink gold hands and markers, while the satin-finished titanium bracelet incorporates BMG studs and a titanium folding clasp. Powered by the caliber 7121, the watch offers a 55-hour power reserve, operates at 28,800 vibrations per hour, and provides water resistance up to 50 meters.
Final Perspective
The Royal Oak bezel has always been both its greatest strength and its greatest vulnerability. With the introduction of bulk metallic glass, Audemars Piguet has addressed a decades-old challenge using modern material science — without compromising design integrity.
It is a rare example of innovation that serves tradition rather than replacing it.
Visit Us
If you would like to explore Audemars Piguet Royal Oak models or discuss modern materials like bulk metallic glass in person, we invite you to visit DNA Watches in New York City’s Diamond District.
DNA Watches
15 West 47th Street
New York, NY
To schedule a private appointment or inquire about availability:
Email: sales@dnawatchesnyc.com
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Appointments are recommended for a personalized experience.