Glass Measurement

[obleo]

I ordered a 30mm diameter glass, it measured 29.88 and was (obviously) too loose. Should glass measure exactly as stated or is the measurement always smaller (like wood)

Thanks

Jim

[WillFly]

Welcome Jim - enjoy the forum.

 

Whenever I've replaced watch crystals, I've gone to a repairer friend of mine who has a massive stock. We get the so-called correct size out of the packet only to discover, sometimes, that the bezel actually needs either a size smaller or larger - in spite of the packet labelling! It can certainly be a problem.

[Mark]

Jim, welcome to the forum.

 

This is reasonably common with replacement glasses. When I order I will usually obtain the one above and the one below and whatever I don't use goes into my parts collection.

[Geo]

Welcome to the forum Jim. You should get answers to most of your horological questions here.

[obleo]

Many thanks for the replies and warm welcome.

Jim

[bobm12]

Welcome Jim,

 

It happens sometimes and it is more like a guesstimate considering you don't really know how the new crystal is going to fit since tolerances are + or -. All that said, one size up and one size down as Mark said is the way to go!

 

Hope this helps,

 

Cheers,

 

Bob

[obleo]

Many thanks Bob.