Q: What bit should I use to drill a hole in glass?
A: You’ll need a diamond-coated or carbide-tipped glass bit. The glass will have to be held very securely so that it cannot spin or flex when drilling. Avoid direct metal-to-glass contact when clamping. Place paper or gaffer tape over the intended hole location and drill through the tape to prevent the glass from chipping. Heat buildup from the drill will quickly crack the glass, so use a spray bottle to cool the bit throughout the drilling operation. Don’t press down; let the drill do the work. To remove shards from the completed hole, use wet sandpaper that has an extremely fine abrasive.
