IRWIN® Blue Groove Wood Power Bit Set, 3 Piece 14 16 & 18mmThe Blue Groove Power is the world's first wood drill bit to use IRWIN's pioneering bi metal technology, creating a drill bit with unrivalled speed and durability even in nail embedded wood. Designed for high speed precision drilling, it marks an end to the frustration that tradesmen experience when their drill bits strike a nail, frequently causing standard flat bits to become locked or break. The secret behind Blue Groove Power's extraordinary