Review on Diamond Cutting Remover Porcelain - π 6mm to 50mm: Efficient Tool for Precise Cuts by Ian Bates
Wet the drill before and during cutting. They seem to be the last.
I had to cut some holes in a floor tile. I saw these ceramic drill bits and thought for the money they were worth a try. I don't think I was expecting much. To my surprise, these bits cut through floor tiles excellently. They don't have a middle bit to guide them. So you need to take a piece of wood and drill a hole the size of the ceramic drill you are going to use. Place this on the work piece, WET the ceramic drill bit (or you'll ruin it) and work the drill bit for a few seconds. Stop, wet the drill again and let it run for a few more seconds. Check if you have a groove. When you do this, remove the piece of wood and continue drilling in small increments, then add more water. I've drilled quite a few holes with several of these bits and they continue to cut well.
- Very expensive
