Lasts up to 10x longer than Bosch CYL-9 Ceramic Drill bit - As wall tiles have become larger and harder, drilling holes in them has become very demanding on a tile drill bit. Thats why Bosch has developed the EXPERT HardCeramic Drill Bit, which is capable of dry-drilling hard ceramics and lasts far longer than our benchmark drill bit for tiles. This specialist hard ceramic bit uses Boschs Carbide Technology the hardest of metals and combines it with an advanced multi-faceted tip design that shares the workload over multiple asymmetric faces. This complex drill bit tip, achievable through fine grinding manufacturing technique, also enables a precise start without skidding and scratching. The Bosch EXPERT HEX-9 HardCeramic Drill Bit is designed for drilling ceramics and can drill holes in hard tiles without lubricant or cooling. Hex shank for a strong connection and maximum torque transmission in three-jaw chucks and 1/4" internal hex tool holders.