Easy to Make Glass Block Lights | Glass Diamond Drill Bit Set for Glass Block | FREE Instructions and Idea Guide 1/2" and 3/4" premium quality diamond core drill bits for wine bottles, glass block, glass jars 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. Make lighted glass block, wine bottle lamps, bird feeders and more