ForgeMaster Tile Max Drill Bits are recommended to be used with drill driver machines into all types of tiles including porcelain, granite and marble. 4x85mm pilot drill used mainly as a starter drill for larger diameter drill sizes. Diamond Cut. No water cooling required as drill is used on very slow speed for maximum efficiency. Unique tip brazing method ensures no tip loss even through the hardest materials. Exclusive design, triangular shank, preventing drill seizure. Heat treated to increase life span of the drill bit. Specially designed diamond ground tungsten carbide tip. Sand blasted finish for increased durability. Specialist flute design enables effective dust extraction. Suitable for all tiles including porcelain class 5. Countertop Display Unit available. Finish: Sanded.