Review on Uxcell Diamond Drill: Cutting Tools for Ceramic and Porcelain by James Roberts

I made climbing holds for a backyard climbing wall out of granite, limestone, and some sandstone. Each requires a .75" to 3" diameter clearance hole that must be screwed to the wall. If I had to guess, I'd say each bit is rated for about 6-10 inches of drilling in hard rock. I use a drill press at about 500rpm, light pressure and dip the stones in cold water as I drill. When I tried to drill without water, the bit burned out and lost all the sand in less than 30 seconds. Keep them cool and they'll do some work for you. I just wish I could find longer ones. In my deepest holes I have to constantly lengthen the bit and clear debris, which gets tiring.