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Glossary

Twinlock crown

A plain-language definition of Twinlock crown — what it is and why it matters on a Rolex.

Twinlock is Rolex's screw-down winding-crown sealing system for its non-dive watches, using two sealed zones to keep water out. It secures models like the Datejust and Day-Date to 100 metres. Its tougher sibling, the Triplock, adds a third seal for dive watches rated to 300 metres and beyond.

Two seals, 100 metres

The winding crown is a watch's most vulnerable opening. The Twinlock crown screws down against two gaskets — one inside the crown tube, one inside the crown — sealing the case to 100 m. It is fitted to dress and everyday Oyster models that don't need extreme depth.

Twinlock vs Triplock

Dive watches use the Triplock crown, which adds a third sealed zone for water resistance to 300 m (Submariner) or far deeper (Sea-Dweller, Deepsea). You can often tell them apart by the small symbol beneath the coronet on the crown: dots, a bar, or a triangle indicate the crown type and metal.

Twinlock crown FAQ

Twinlock crown, answered.

What is a Twinlock crown?

Twinlock is Rolex's screw-down crown system with two seals, used on non-dive Oyster watches like the Datejust. It provides water resistance to 100 metres.

What is the difference between Twinlock and Triplock?

Twinlock has two seals and protects to 100 m; Triplock adds a third seal for dive watches rated to 300 m and deeper. Triplock is found on the Submariner, Sea-Dweller, and Deepsea.