This set includes four drill bits with diameters of 5.5mm, 6mm, 7mm, and 8mm. These drill bits are designed for drilling into very hard materials such as Ceramic, Granite, Terracotta, and Porcelain. They do not require water cooling as the internal wax acts as a lubricant. For optimal efficiency and longevity, use these bits with a high-speed mains drill. These Mexco tile drill bits can cleanly cut through porcelain, ceramic, and stone tiles without the need for water, thanks to a wax filling that melts, lubricates, and cools during drilling. The bits feature a hex fitting for secure chuck stability and are suitable for use on stone worktops and other kitchen or bathroom fittings. For excellent performance and cost-effectiveness, choose Mexco dry diamond tile drill bits. Key features include no water requirement due to the wax filling, clean cutting on all tile types including porcelain, suitability for bathroom and kitchen fittings, a non-slipping hex end, a professional diamond-tipped finish, compatibility with high-speed corded drills, and a minimum required drill speed of 1800 rpm.