What size hole saw drill bit do I need to use to make a 14mm hole ?

14

 

You'll need glass drill bits to do it.. you can't just drill glass with anything man lol

 

9/16 if you don't have metric drill bits.

 

Ya hooked me!
I gotta know; what glass are you trying to drill a hole in?

 

I do it to make bongs, etc. Those bits are pricey.

 

I use a dremel with a rotary file.
Patience!!!!!
Practice first.