IRWIN Tools 1881325 Impact Performance Series 135 Split Point/Masonry Drill Bit Mixed Set, 6-Piece Built for maximum durability and long life with impact drivers One-piece construction withstands higher torque loads than standard quick-change bits Made from premium high speed steel with black oxide finish for added corrosion resistance 1/4" quick-change shank is designed to work with impact drivers, and reduces slipping in standard drill chucks Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high torque output