Tempered Glass ?

[thebluemonkey]

I want to drill a hole in the bottom of a glass vase. I have access to coolant, a pillar drill and the correct drill bits. I have heard that tempered glass shatters when you try and drill it and was wondering if anyone knows how you tell if glass is tempered ?

[sirtophamhat]

I worked in a glass shop for a few months. In my erperience, its pretty hard to tell without hitting it. I really wouldnt try and drill it, or if you must than be careful, go slow. We never tried to cut or drill anything tempered, I recall being told that it was cut to size, then tempered. Makes sense considering how you finish a cut after scribing it... With panes of glass you can sometimes tell by the edges, but I dont know if that was just some prep work thing that was done before it was sent to us.

[thebluemonkey]

Oh well, that's what I was afraid of, back to the drawing board. Thanks anyway.

[Balmoral Green]

It's not gauranteed to break, but more than likely it will. Do you feel lucky?