The Irwin Tools 3041017- 13/16" X 6" SPEEDBOR MAX Drill Bit is the Fastest Speedbor spade bit ever. Tri-Flute design for faster chip ejection. Cutting spurs have 3 cutting edges for added durability. Full screw tip allows bit to self feed. Grooved hex shank prevents slipping in drill chuck or bit extension. Fits all standard 1/4" quick change chucks.