IllustrationDisassembled crown with miniature O-ring visible
Replacing a crown gasket

Role of the crown gasket

IllustrationDiagram of crown sealing with gasket in position
Role of the crown gasket in sealing

The crown gasket, sometimes called the crown ring, provides the seal at the passage point of the winding stem. It blocks water, dust and used grease. Replacement is essential after loss of water resistance or a complete service.

Browse our watch crown gaskets in several diameters.

Types of crown gasket

IllustrationThree miniature crown gaskets lined up by diameter
Types of crown gasket
  • Exposed gasket: visible on the stem, individually replaceable.
  • Hidden gasket: integrated inside the crown. It is preferable to replace the whole crown.

This guide covers the exposed gasket.

Replacement steps

IllustrationFine tweezers extracting a tiny crown gasket
Replacement steps for the gasket
  1. Remove the stem and crown from the case by pressing the movement's locking pin.
  2. Locate the gasket on the stem: it sits in a dedicated groove.
  3. Peel off the old gasket with a plastic toothpick or pricker. If it is hardened it may break apart.
  4. Measure the diameter of the groove with a digital micrometer: that is the dimension to match for the new gasket.
  5. Lubricate the new gasket silicone grease to extend its service life.
  6. Slide the gasket along the lower part of the stem to its groove.
  7. Test the fit : reinsert the stem into the crown tube. A slight resistance should be felt.
  8. Reassemble the movement and close the watch.

Water-resistance check

IllustrationPressure bench testing the water resistance of a watch
Final water-resistance check

If the crown remains loose the gasket diameter is too small. Pick a slightly larger outer diameter. A crown that turns too hard means an oversized gasket.

Required tools

IllustrationAntimagnetic tweezers, loupe and gaskets on a watchmaker mat
Tools to work on the crown
  • Micrometer or digital caliper
  • Plastic toothpick or pricker
  • Watchmaker tweezers
  • Silicone grease
  • Watchmaker screwdriver

Available in our watchmaking tools.

The crown gasket is responsible for roughly 30 % of water ingress, just after the case-back gasket : never neglect it during a service.
The crown gasket is the smallest guardian of water resistance, and often the most forgotten.

Common mistakes to avoid

  • Forgetting to grease the tube gasket
  • Forcing the winding stem without pressing the release pin
  • Picking an approximate diameter without a caliper

FAQ

How do I tell an exposed gasket from a hidden one?

The exposed gasket is visible on the stem as soon as it is removed. The hidden gasket cannot be seen: it sits inside the crown itself.

Should the crown gasket always be lubricated?

Yes. Silicone grease extends its suppleness and sealing. See lubricate a watch gasket.

Why does my crown stay stiff after replacement?

The gasket is too large or insufficiently lubricated. Reduce the diameter or add grease.

How long does a crown gasket last?

Between 2 and 4 years in everyday use. Check at every service.

Written by the Joint-de-Montre.com team · Updated 22 May 2026