For rotary drilling only. Includes 5/32 pilot bit which must be used first. Ideal for drilling porcelain tiles up to a scratch hardness of 8. The drill bit will not walk, tape or center punching is no longer needed. Flat bottom parabolic flute ensures fast and efficient removal of drill dust and prevents clogging. Cuts nice, clean holes with very little or no chipping; operate drill motor 400-600 RPM. Ideal for drilling porcelain tiles up to a scratch hardness of 8Rotary drilling onlyCobalt and tungsten carbide tipChrome vanadium steel shankUnique 4-face point grindingFlat bottom parabolic flute ensures fast and efficient removal of the drill dust and prevents cloggingExtreme low drilling pressure with excellent centering prevents walking - no tape or center punching neededDiamond ground PORC+ cuts nice, clean holes with very little or no chipping