1, Tapered HSS drill bit with wide flutes for drilling fast & clean pilot holes.
2, 4-cutter counterbore cuts faster and provides smooth countersinking.
3, Counterbore attachehed with screw firmly, and can be adjusted for controlling pilot hole depth.
4, 1/4″ quickchange shank reduces slipping in standard chucks and is compatible with all 1/4″ quick-change chucks, including impact drills
5, Size: 6#, 8# & 10#, other sizes available