The DEWALT DT71582-QZ 23 Piece Straight Shank Combination Drill Bit Set is a professional drill bit set for masonry wood metal and plastics. Carbide grade with innovative tip design and optimised milled flutes for fast accurate drilling. Masonry bits are designed to produce concentric holes for better fixings fitting. HSS black oxide metal drill bits are precision-ground to an optimum 118° for rapid drilling and long life. Top quality high strength chrome vanadium wood drill bits with centre location brad point and sharp outer spurs give clean accurate holes.