The Irwin 4x Blue Groove Flat Bits cut the timber 4 times faster than standard flat bits. They have a patented groove point and cutting edge designed to cut the timber rather than scrape. The parabolic scoop speeds the removal of waste wood. The double-cutting spurs scribe outside of the hole, reducing breakout and resulting in a clean hole. A thicker cutting edge ensures a long drilling life. The shanks are 10% larger for added durability. The 1/4" hex shank prevents the bit from slipping in a drill chuck or allows its use in a quick-change hex holder. This 17-piece set comes in a robust storage wallet.