Speedbor 1877239 IRWIN Tools Max Wood Drilling Bits, 4-Inch, 6-Piece 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 Shorter overall length for drilling in tight spaces. Ideal for holes up to 2" deep 1/4" quick-change shank reduces slipping in standard chucks and is compatible with all 1/4" quick-change chucks, including impact drills