Why fit a new crystal gasket
The crystal gasket, usually made of Hytrel, holds the crystal in the bezel and contributes to the water resistance of the watch. On dive models it is essential for pressure resistance. Every time the crystal is removed, this gasket must be replaced: it deforms, hardens or sticks to the glass.
You will find compatible references in our catalogue of watch crystal gaskets.
Fitting steps
- Open the watch and remove the movement so you can work on an empty case.
- Remove the old crystal with a crystal press or a suitable extractor.
- Remove the old gasket completely. If it is hardened, lift the fragments with a pricker or sharp tweezers without scratching the finish.
- Clean the groove of the case. For stubborn residue use an ultrasonic bath or a warm soapy soak, then a soft brush.
- Dry thoroughly before fitting.
- Fit the new gasket by pushing it into the groove with tweezers in small successive presses.
- Check that it sits flat: the gasket must be even and continuous all the way round.
- Refit the crystal with the press, spreading the pressure evenly.
Technical tips
Unlike the crown gasket and the case-back gasket, the crystal gasket is not lubricated. Silicone grease spoils its hold. Be patient: if the gasket lifts out of the groove, hold one section down with your finger while you fit the rest.
Tools required
- Watch crystal press
- Watchmaker's tweezers
- Pricker or pin vice
- Ultrasonic bath (optional)
- Lint-free cloth
Find these references in our watchmaker's tools section.
The water resistance of a watch depends 90 % on the condition of its gaskets, not on how good the case looks.
Common mistakes to avoid
- Reusing the old deformed crystal gasket
- Lubricating the crystal gasket (grease ruins its hold)
- Forcing the crystal in without a proper press
FAQ
Do you always have to change the crystal gasket when replacing the crystal?
Yes. The gasket deforms when removed and loses its sealing properties. A new gasket is essential.
What material are crystal gaskets made of?
Hytrel is the standard material. It combines elasticity with long-term resistance to compression.
Can a crystal gasket be greased?
No. Silicone grease is reserved for O-rings on the case-back and crown. On the crystal it spoils the hold.
How do I measure the right diameter?
See our guide measuring a watch crystal gasket before ordering.