IRWIN Tools 1881080 Impact Performance Series Concrete Screw Drill-Drive Installation Set for 3/16-Inch and 1/4-Inch Screws, 7-Piece Built for maximum durability and long life with impact drivers Innovative pressed carbide tip with aggressive cutting angles for faster drilling and longer bit life One-piece construction withstands higher torque loads than standard quick-change bits Black oxide finish resists corrosion and increases life of bit Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high torque output