Irwin Tools 1838528 Accessories, Power Bit Impact T40 x 2" (Pack of 10) These insert bits feature precision-tip geometry for superior fitment and reduced stripping Insert bit is made from heavy-duty, cold-forged, high-grade steel to withstand high-torque output Impact drivers provide these screwdriver bits with high durability and long life Power Groove is designed for compatibility with IRWIN Impact Performance Series magnetic screw-hold attachments These insert bits have a black oxide finish to resist corrosion and increase life