Speedbor IRWIN Tools 1866035 SPEEDBOR MAX Wood Drilling Bit, 4-inch by 3/4-inch;

The 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 (3) 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" quick-change chucks, including impact drills.