Standard sapphire watch crystal bevel ?

[HauteHippie]

Hey folks. Does anyone know, offshore maybe (?), what is the standard bevel angle used on watch crystals? It does not look like a 45° angle on most of mine. I'm thinking maybe 30° or so? Anyone know?

Thanks,

Chief

[txcollector]

I can check but I believe the engineering constraints will dictate 40°. I have to search my notes though.

[HauteHippie]

Thanks, bud. Let me know when you get a chance to look it up. I guess it probably varies from one make to another, too. So there may be no right answer, other than a maximum.

[RWG Technical]

It varies between the crystals, there is no standard that I have noticed. Typically you need a slight chamfer on the edge to be able to insert the crystal into the seat, but otherwise it's all over the place...

Most critical is the diameter, anything beyond + - 0.05mm of the required dimensions and you could have problems, too loose or too tight in the compression ring.