DeWALT Extreme 2™ Metal Drill BitsUp to 4X faster than conventional HSS DrillsCleaner, more accurate, burr-free holes due to recessed cutting wingsUnique metal tip starts cutting on contact eliminating walking (3.2mm and above)3 flat shank (5.0mm and above)12.0mm and above have a reduced shank (11.4mm dia)Suitable for Steel, Alloys, Thin Materials, Wood & PlasticsDrill Bits & HSS/Masonry SetsMetalworking drills.