I've got about a dozen old mens quartz watches, all came with round flat mineral glass crystals, but are missing on most. I need to replace them. All but one has a nylon retainer. Don't know if the other is missing or never had one. They all measure between 29.2mm and 29.5, and as near as I can tell should be approx. 1mm thick.

So here's my question..... Should they be straight sided on the edge? Or, should I allow for the nylon retainer? Does the retainer fit between the glass and the bezel, or does the retainer sit on top of the glass?

In other words, how do I order correctly and how do I install them. I do have a crystal press.
I have the correct diameter?? hopefully.

As I understand it, when the crystal is pressed in, it should have a sharp clear snap, into the bezel.

So, who has done this and what else do I need to know before I order a bunch of wrong crystals.!

Hi Dave,

try those videos about fitting glasses:

https://www.youtube.com/watch?v=HFvcgmIM2B4
https://www.youtube.com/watch?v=4RvDyhSsIYo
https://www.youtube.com/watch?v=mZO2t848wiM

each move is about different type of glass. I hope it will give you some insight.

Rafal

Thanks Rafal, I did look at those. My biggest question now is how much should be allowed for the compression ring that sits between the bezel and the glass. Esslinger also has how to videos, and one comment they have made is that you need to add .1mm if it has the nylon gasket. I sure don't understand that. I'd think you would deduct, not add.

I think they are right. Because of that nylon bezel glass could have smaller diameter and you have to add 0.1 to receive proper tension between bezel and case as its for waterproof watches. I suppose it just squeez nylon and seal connection.
Fitting glasses is a tricky thing, like with pocket watches where bezel is not a full circle and you have to make a few measurements and still not be on the spot

What I may suggest, you could write an email to Mike - author of those videos and ask for details or explanation. He's very helpful and a professional watchmaker.

Good point, Rafal, Might just do that.
I'm still trying to figure this out before I order.
I guess the plus .1 depends on where you get your original measurement. I measured the bezel since the crystal was already missing. So, in that case I would think I have the correct size and the .1 is already included?

I think after you measure bezel you suppose to add .1 to get it properly fitted, it has to be bigger than bezel to have proper tension between glas, nylon and bezel. Meybe smeone here has some more experience and could advise.