Glass Drill Bit Set, 5 pcs Diamond Drill Bits Hole Saw Bottle Extractor Remover Tool for Glass Marble Granite Fiberglass Ceramic Tile 4-12mm

They either need a drill press or have something with a hole the same diameter that it passes through as a guide. like a little wood block with a predrilled hole stuck to the glass so it doesn't slide around. They have no pint and rather cuts a little circle out like a hole puncher. A guide that is water fill-able gives the bits a little longevity. without cooling they last about 2 holes. With water they seem to last a long time. They should come with a predrilled plastic block with different sized holes and double sided adhesive tape to stick it where the hole is needed. I'd give them a 5 if they came with that. That makes them last as one can then wet drill.

If you are trying to drill a glazed pot, angle the bit to rough up the surface where you intend to put a hole, otherwise if you try to drill straight down the bit slides all over (for me it did, anyway). And it really took what seemed to be a loooong time and lots of pressure to make a hole all the way through. Hope it goes better for you!

These are awesome. As other reviews have mentioned, put a little water on your drilling surface, start drilling at a slight angle, and PRESS DOWN. You also have to start the drill BEFORE you press into the surface of whatever you’re drilling (not like driving a screw, where you touch the screw head first, then start the drill). Made perfect drainage holes in a number of ceramic pieces I can now use as planters.

Purchased for a craft project. Drill bits worked great for creating a hole in a Jack Daniels bottle for our lighting project.

Wanna drill glass? Then these are your choice! They work very well. I've tried the metal carbide glass bits and they usually always cause a crack or break the bottle. These do not. They cut a super nice hole. REMEMBER...plenty of water to keep the glass cool...and not too much pressure on the drill. Let the bit do the work!.