Irwin Speedbor 3041007 Auger Boring Bit, 1 in Dia, 6 in OAL, Tapered Flute, 3-Flute, 1/4 in Dia Shank, Hex ShankThe Irwin Speedbor MAX SPEED wood drilling bit is the fastest Speedbor ever. The speed tip features a full screw point that allows bit to self feed, as well as three cutting spurs for faster, cleaner holes, less breakout and extended drilling life. The tapered tri flute design allows for faster chip ejection and less binding. Its grooved hex shank prevents slipping and fits all standard 1 4 in quick change chucks, including impact drills. Unit: EA