AP Chronicles Series EP. 6: Details on the AP Watch Case
Following our previous article, the story behind the creation of the case for the first Audemars Piguet Royal Oak was explored from various angles, revealing just how intricate the process of crafting an AP watch truly is and why the AP Royal Oak carries such a high price tag.
However, the journey of creating the first AP Royal Oak is far from over. This article continues that story, as there is still much to learn for those enchanted by the charm of this brand. We will gradually piece together the puzzle of its history, and once complete, the full grandeur of the AP watch will become clear, answering why AP timepieces are so enduringly revered.
Waterproof Seals and Gaskets
In traditional watchmaking, a seal is a small rubber component carefully placed in the groove between the three main parts of a case. Once the case is assembled, the seal is tightly compressed and hidden from view. However, the original authentic AP Royal Oak was different. For one, the thin black line of the seal around the bezel was visible. Above all, its properties were extraordinary: 5.59 mm thick (uncompressed), over 4 mm wide, with a complex shape combining round and octagonal sections, and featuring 9 holes nearly 2 mm in diameter (8 for the through-screws and 1 for the winding stem). This was the key to its effective water-resistance system.
The seal is compressed by the pressure of the eight hexagonal screws that support the overall rigidity of the case, situated between the bezel, the case back, a thin gasket ring—which is detached from the movement—and a narrow inner rim (flange), which is detached from the dial.
Naturally, the production process evolved. The 5402 model, for instance, had two types of installations: one using black rubber seals and the other using translucent silicone. While the sturdier black rubber seal had the disadvantage of being difficult to control—potentially resulting in a honey-like appearance or outgassing that could damage the movement's lubricants—the translucent silicone offered greater stability and flexibility, though it was perhaps less durable.
Occasionally, some seals were unsigned, while others featured the Audemars Piguet watch symbol, the "SWISS MADE" origin mark, and a serial number. Later models added more details as it became easier to control the quality of the seals.
The Eight Hexagonal Screws
The eight hexagonal screws punctuating the octagonal bezel were the most unique and distinctive elements of the 1972 Audemars Piguet Royal Oak. Throughout the 1970s and 1980s, collector sentiment was such that some joked, "Are they kidding with a price like this when they don't even seal the gaskets?"
The screw head slots look as though they could be turned with a screwdriver, but the shape of the head is actually the opposite; because they are embedded into the hexagonal openings of the bezel, they cannot be turned. In other words, these are non-rotatable screws! The secret to this system lies in threading the hexagonal screws into circular nuts pulled from the back of the watch, which serve to create a secure seal.
However, while this system protected the movement perfectly, it did not prevent water from seeping through the screws and nuts. As Wilfred Berney, founder of the Audemars Piguet customer service department who worked during the creation of the Royal Oak, noted: the screws of the first 300 Royal Oak watches were made of steel. When exposed to seawater, the water would flow along the screws and accumulate salt.
“Seawater would attack and corrode them severely, bypassing Genta’s 'Diving Helmet' water-resistance system. Even though we could use oils and other products to help remove the case screws, it didn't work for the bracelet screws. The only way to solve this was to manufacture special drill bits and a complete set of tools to drill through the screws and reach the rotating part of the bracelet, then dislodge them using ultrasound technology.” Following this incident, the screws of authentic AP Royal Oak watches were changed from steel to white gold.
Buy Authentic AP Watches at Pixiu Watch
The story of the Royal Oak case creation is not over yet. Stay tuned for the next episode in the upcoming article from Pixiu Watch. If you are looking to own an authentic AP Royal Oak watch at a great price, look no further than Pixiu Watch. We are a pre-owned luxury watch dealer that curates precious timepieces, helping you find the perfect charm in the beautiful watch you desire, while providing professional consultation and advice from those who have long understood the passion of collectors.
For further inquiries, please contact us at 096-939-9292 (Oat) during business hours.
Reference
- THE FIRST ROYAL OAK CASES, retrieved June 27, 2023, from https://apchronicles.audemarspiguet.com/en/article/the-first-royal-oak-cases
