Guy King wrote:
The message from Chris Bacon contains these words:
You can drill toughened glass, you just have to be careful
(and very slow), and use a fine abrasive and rod as ?? ago.

You sure about that? As I understand it, once the compressed outer layer
is broached the whole thing goes bang no matter what. Prince Rupert's
Drops and all that.

I drilled through a toughened windscreen some years ago, which
was OK..... I can however tell you that using a glass cutter is
not a good idea. Amazing how far the bits go.