The Lenox Self-Feed Bit features a high speed steel cutting edge for excellent durability in nail-embedded wood. The bit has a chamfered edge that allows the bit to be removed quickly after drilling. The aggressive lead screw tip pulls the bit through material quickly and with less effort. The bit also features a longer shank that cuts 4" x 4" without an extension, as well as an impact hex shank for quick bit changes. An extra lead screw and wrench are included.