IRWIN Tools SPEEDBOR Max Wood Drilling Bits, 6-Inch length, 10-Piece (1801022) Wood drill bit set includes bits with three cutting spurs for faster, cleaner holes, less breakout, and extended drilling life Full screw-point tip allows bit to self-feed for ease of drilling Tapered tri-flute design for faster chip ejection and less binding. 1/4" quick-change shank reduces slipping in standard chucks and is compatible with all 1/4" quick-change chucks, including impact drills