3 Pack of 5/16" Diamond Core Drill Bit For Glass and Tile | Free Beginner's Glass Drilling Guide 5/16" Diamond Core Bit for Glass and Tile; Fits your hand drill or drill press FREE 4 page drilling instruction guide. FREE 5 page decorating ideas guide FREE shipping in the US. No risk - 100% money back guarantee EASY - Use your kitchen scrubbing sponge for drilling. It holds the glass and cools the drill bit. Drill glass, wine bottles. ceramics, plates and tile