General Tools Adjustable Pilot Bits, Set of Four 1/4", 4 Piece
Each tool in the #34ST Adjustable Pilot Bits, Set of Four can drill, countersink and counterbore a precision screw hole in one step.
Made of hardened high-speed steel
Black oxide finish deters rust
1/4 in. hex shanks prevent slippage in electric drills and allow use in power screwdrivers