Horological repair, restoration and machining
All materials change shape when exposed to temperature or pressure variations. Watch cases are usually made up of 3 main components; case, crystal and crown. Gaskets seal the mating components.
Cases, case backs and crowns can be precious metals, steels, brass, plastics or
Crystals can be plastic, mineral glass or sapphire.
Gaskets can be plastics or various rubber compounds.
Water resistance - Materials