Finishing Diameter: 3/8"Pilot Bit Size: 5/32"Set Contains 1 - Pilot Bit, 1 - Finishing BitIdeal For Drilling Porcelain And Hard Tiles Up To A Scratch Hardness Of 8Cobalt And Tungsten Carbide TipTip Design Will Prevent The Bit From WalkingChrome Vanadium Steel ShankUse In Rotary Mode Only, Do Not HammerMax RPM: 400-600