Irwin 3041004 Speedbor Max 3/4-Inch by 6-Inch Self Feeding Spade Bit A fast speedbor spade bit that features a Tri-Flute design with a fast chip ejection Cutting spurs have 3 cutting edges Grooved hex shank prevents slipping Fits all standard 1/4-inch quick change chucks Full screw tip allows the bit to self feed