Standard spade bits burn out before they clear the workpiece - the chip evacuation fails, the bit grabs, and you get a scorched entry hole and a ruined bit on the second hole. When you're boring two dozen holes for running wire or pipe through floor joists, you need a bit that feeds itself, clears chips continuously, and doesn't grab on exit. 2-inch self-feed wood boring bit with a threaded feed screw that pulls the bit into the work at a controlled rate without hand pressure - the bit does the work. Wide chip? on the leading edge ejects material fast enough that the hole clears before the bit exits, eliminating the grab-and-shudder that damages workpieces and fatigues the operator. Key Specs Diameter: 2 inches - correct for running 3/4-in and 1-in conduit, PVC pipe, and NM cable Feed: Sel Stocked at Crofton Lumber and Akron Lumber.