Review on Premium Diamond Granite Ceramic Porcelain Bathroom Collection by Michael Hudson

I've only used one of the bits so far but it's worked well. I used the method of drilling a slightly larger hole (than the drill) 2 times, clamped the porcelain stoneware and onto the drill press 2 times, filled the hole with water 2 times and ran the drill until I had a decent number of cuts tile. (about 1/16 inch) then I removed 2x, built a dam with putty, filled with water and finished drilling. All in all it took a few minutes. I've seen the bits last at least 10 holes. For the price of the set it is worth the money. I would buy again.