Silicone watchmaker gasket sheet 0.50 mm for case

A 0.50 mm thick silicone case gasket engineered for the maintenance and restoration of mechanical, automatic and quartz watches. Soft, durable and chemically stable, this seal restores long-lasting water resistance against splashes, dust and sweat.

Product overview

This silicone gasket, marketed under reference Joint-SILI-0-5, is specifically calibrated to a cross-section of 0.50 mm, one of the most common thicknesses for entry-level and mid-range watches. Silicone offers excellent flexibility at both low and high temperatures, very good resistance to ultraviolet light and a long shelf life. It is therefore an excellent choice for dive watches, chronographs and any timepiece exposed to frequent temperature shifts, such as moving from an air-conditioned office to a hot beach.

Technical specifications

• Thickness: 0.50 mm
• Reference: Joint-SILI-0-5
• Family: silicone watch gasket
• Material: high-purity silicone (and NBR available on some references)
• Packaging: per unit or by batch
• Compatibility: standard horological case-backs
• Application: case-back sealing for mechanical, automatic and quartz watches

When to use it

Use this 0.50 mm silicone gasket whenever the original case-back seal measures the same cross-section. It is particularly recommended for dive watches, chronographs and any watch routinely subjected to significant temperature changes. Silicone retains its softness in cold conditions and resists ultraviolet exposure, making it a reliable long-term solution for sports watches and timepieces stored in display cases under light.

How to install

1. Open the case-back with the proper tool (knife for snap-on, wrench for screw-down).
2. Remove the old gasket with pegwood, taking care not to damage the groove.
3. Clean the groove with isopropyl alcohol and a microfibre cloth.
4. Verify the inner and outer diameter of the new gasket against the original.
5. Apply a thin layer of silicone-compatible watch grease.
6. Lay the gasket flat in the groove, free of twists.
7. Refit the case-back and perform a dry-air water-resistance test.

Quality and origin

Each batch is shipped from our French workshop and dimensionally inspected before packaging. The silicone we use meets professional horological standards and complies with the durability requirements of daily-worn timepieces.

FAQ

Is silicone better than NBR?

Silicone is better against temperature and UV, while NBR resists oils and abrasion. Choose silicone for sports and dive watches, NBR for general-purpose dress watches.

Will a 0.50 mm gasket fit my watch?

Only if the original seal measures 0.50 mm in cross-section. Always measure your old gasket with a digital caliper before ordering.

Can I use silicone grease on a silicone gasket?

Yes. Standard watchmaking silicone grease is fully compatible and significantly extends the service life of the seal.

Pairing with our other gaskets

For complete watertightness we recommend renewing the case-back gasket, the crown gasket and, where applicable, the crystal gasket during the same service. A consistent set of fresh seals delivers a far better water-resistance result than replacing a single component. Our online catalogue lets you cross-reference inner diameter, outer diameter and cross-section to find the exact match for your watch, whether it is a Swiss-made automatic, a Japanese diver or an entry-level quartz.

Storage and shelf life

Keep your spare gaskets in a cool, dry drawer, away from sunlight, ozone-emitting devices and aggressive solvents. Stored under these conditions, an NBR or silicone O-ring retains its mechanical properties for several years. Inspect each gasket before fitting: it must be perfectly circular, free of cuts and free of permanent set. Discard any seal that shows signs of crystallisation or tackiness on the surface.