IRWIN SPEEDBOR 3041004 Auger Bit Wood Boring Bit, Tapered Flute, 2-3/8 in L Flute, Hex Shank, 1/4 in Dia Shank                 The IRWIN SPEEDBORA(R) MAX SPEEDa,,c wood drilling bit is the fastest SPEEDBORA(R) 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.