The Irwin masonry drills bits are designed for fast and efficient drilling in brickwork, concrete and breeze block, especially with cordless drills. They drill up to 60% faster than competitive drill bits whilst maintaining the same high durability. The single flute design ensures faster dust removal for increased drilling speed, with the unique, pressed diamond-ground carbide tip allows for aggressive cutting and the carbide tip design also ensures 20% longer life compared to previous Irwin masonry drill bits. The bits are made with a chrome vanadium body with high carbon content which allows more hardening and a stronger bit for maximum rupture strength. Irwin Masonry Drill Bit for Cordless Drills. Specifications:Diameter: 4.5mm.Total length: 45mm.Working Length: 85mm.