IRWIN Speedbor MAX 3/4 inch bit - The Fastest Speedbor spade bit ever, featuring a Tri-Flute design that allows for faster chip ejection. The Speedbor MAX has cutting spurs with three cutting edges for added durabilty. A full screw tip allows the bit to self feed. The grooved hex shank prevents slipping in drill chuck or bit extension. Speedbor MAX bits fit all standard 1/4"" quick change chucks.