Review on Complete Hole Saw Kit With Diamond Drill Bits And Adjustable Guide Jig For Glass, Ceramics, And Tile - 15 Pieces, 6-50Mm Size Range by Jason Holt

I don't do porcelain work for a living so these are perfect for me. I spent 75 dollars at Lowes for three drills that didn't work. I used mine on a drill press with the project submerged in water at 300 rpm and light pressure. the holes came out perfect and the drills cut rapidly. If I was a a pro I would buy an expensive set but at only a few holes per year these will last a lifetime. The guide is a must and worked perfectly for me. They came three days after I ordered them so that was another plus.