Have any of you ever drilled a hole in a piece of glass ? I'm not talking about thin window glass but something more substantial ? I need about a 3/8 " hole through something about as thick . I'm sure there is a special bit for this , right ?
Drilling a hole in a pane of glass or a mirror is simple. The key is to use a carbide bit made especially for glass and tile (see photos). You’ll find these bits at most home centers alongside other drill bits or ceramic tile tools.
Because glass is extremely smooth and hard, the bit will want to wander as you start drilling. To give the bit a foothold, tape a small scrap of dense cardboard (like cereal box cardboard) to the glass. Begin at very low rpm to create a dimple in the glass, then remove the cardboard and continue at about 400 rpm. If you’re drilling on a horizontal surface, you can pour a little oil on the area.
Make sure the glass is firmly supported on the backside and place only very light pressure on the drill; press too hard and you’ll crack the glass. The bit creates a clean hole on the side it enters, but usually chips the edges of the hole on the other side.
Note: You can’t drill tempered glass.
Can a center punch be used to keep the bit from walking?
I'm not drilling a pane of glass . The glass is much thicker .
I'm pretty sure it's not tempered .There’s a video or 3 on YouTube using the diamond cutters and I’ve done it before. Cutting and drilling tempered glass will net mixed results with the carbide. It will shatter. Check the vids.
Can a center punch be used to keep the bit from walking?
That's what I'd do. I have one of those spring loaded models.