The Rolex winding crown

Last Updated on January 25, 2025 by Jason

Rolex watches have long been associated with innovation, precision, and durability. Among the many defining features of these iconic timepieces, one of the most critical components is the Rolex winding crown. The crown serves a vital function beyond just setting the time. It’s also the key to one of Rolex’s most remarkable achievements, water resistance. The development of Rolex’s patented waterproof crowns, began with the legendary Oyster case in 1926. This set new standards in watchmaking and established the brand’s reputation as a leader in the industry.

Screw-down crown

In 1926, Rolex introduced their first truly waterproof wristwatch, called the Oyster. This groundbreaking innovation was named after the tightly sealed shell of an oyster. It was designed to protect the delicate movement inside from moisture and dust. The secret to this protection lay in the screw-down caseback and bezel, but most importantly, in the screw-down winding crown. Prior to this, winding crowns were a weak point in many wristwatches, allowing water and debris to enter the case. Rolex’s development of a screw-down crown with a secure gasket system changed that forever. The company has continued to refine this technology over the decades.

The importance of Rolex’s waterproof technology is perhaps best exemplified in its screw-down crown system. Unlike other brands that used friction-based crowns, Rolex developed a crown fitted with a metal gasket that screwed directly into a tube inside the case. This gasket would compress when the crown was screwed down, creating an airtight and watertight seal that prevented any moisture from seeping into the movement. This technology was integral to the durability of the Oyster case, which allowed Rolex watches to survive in conditions that would have ruined other timepieces.

The Rolex Twinlock winding crown

For many years, the basic screw-down crown design worked well across Rolex’s range of watches. However, when Rolex developed the Submariner in 1953, a professional dive watch, they realised that they needed to enhance the water resistance even further. The Submariner was designed for underwater exploration, where it could be exposed to extreme pressures. To meet the increased demands, Rolex introduced the Twinlock winding crown, a major advancement in the brand’s waterproofing technology.

The Twinlock system introduced two O-ring gaskets made from synthetic materials instead of the traditional single metal gasket. The first O-ring was positioned under the crown, creating a seal between the crown and the case, while the second was placed inside the tube, surrounding the winding stem. This dual-seal system, hence the name “Twinlock,” ensured that water could not enter the case even if the crown was unscrewed. The Twinlock system became a critical feature on many Rolex models, providing them with superior water resistance.

The Rolex Triplock winding crown

By 1970, Rolex had once again pushed the boundaries of watchmaking with the introduction of the Triplock winding crown. As the name suggests, this crown features three sealed zones for maximum water resistance. The Triplock crown was first introduced on the Sea-Dweller, a watch developed for deep-sea divers who needed even more robust protection than the Submariner offered. The Sea-Dweller could withstand depths far greater than those the Submariner was designed for, thanks in part to the Triplock crown’s three gaskets, two within the tube and one under the winding crown itself.

The Triplock system would later be adopted across all of Rolex’s dive watches, including the Submariner and the Deepsea. Today, all of Rolex’s professional dive watches feature the Triplock crown, contributing to their incredible water resistance.

Markings on the Rolex crown

On vintage Rolex watches, especially those made before the 1960s, the winding crowns display distinctive markings. These early Rolex crowns are often seen with a cross symbol beneath the brand’s iconic coronet logo. This cross is not a simple design choice, it represents the “patent cross,” signalling that the crown and its technology were patented. On some vintage models, instead of the cross, you might find the word “Brevet,” which is French for “patent.” These early markings are of particular interest to collectors today, as they tell the story of Rolex’s relentless drive for innovation in the early years of waterproof watch development.

After the introduction of the Twinlock and the Triplock winding crowns, Rolex introduced a new marking system to indicate the type of crown and metal used. Rolex uses three dots to indicate a Triplock crown. On steel models, the three dots are evenly sized, on gold models, the centre dot is larger, and on platinum models, the centre dot is smaller than the outer two. This clever system provides an easy way to distinguish between materials while maintaining the clean, elegant design that Rolex is known for.

For collectors of Rolex watches, the markings on the winding crown provide valuable insight into the construction and history of the watch. A simple glance at the crown can reveal not only the type of winding crown mechanism but also the material of the watch. For instance, if you see a single dot, you know it’s a Twinlock platinum crown. However, if you see two dots, it’s likely a Twinlock white gold crown. Three dots indicate a Triplock system, and the size of the dots can tell you whether the watch is gold or platinum.

Summary

In conclusion, the winding crown on a Rolex is much more than a simple tool for setting the time. It is a crucial part of the watch’s waterproofing system and a testament to Rolex’s commitment to excellence. Whether it’s the original screw-down crown, the Twinlock system, or the advanced Triplock design, the winding crown plays a pivotal role in ensuring the durability and reliability of Rolex watches. For vintage watch enthusiasts, understanding the markings on the crown can unlock deeper knowledge about their timepieces and the technological advancements that Rolex has introduced over the decades.

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