Diamond grit edged 4mm tile drill bit, ideal for accurately drilling hard tiles. Must be used in conjunction with our Universal Drill Bit Guide and Water Cooling System. Slotted bit design for easy waste removal. Ideal for use with most cordless drills on a slow speed setting. Drills hard tiles such as porcelain, granite, quarry, stone, marble, terracotta as well as ceramic tiles. The number of holes this drill bit will cut will be greatly reduced on harder types of porcelain. If you have multiple holes to drill, we recommend purchasing more than 1 drill bit or upgrading to our professional diamond drill bit range.