IRWIN 8-Pack Assorted High-Speed Steel Right Handed Twist Drill Bit Set

Tapered drill with widened flutes for drilling fast, clean pilot holes. Adjustable four-cutter counterbore cuts and clears chips quicker for fast, smooth countersinking. Counterbore attaches to flats on shank with two hex screws for a secure fit, and can be adjusted for controlled pilot hole depth. 1/4-In quick-change shank reduces slipping in standard chucks and is compatible with all 1/4-in quick-change chucks, including impact drills.