IRWIN 1890770 Flexible Installer Drill Bit with Screw Tip, 9/16-Inch Shank, 36-Inch Length Screw tip with aggressive pitch delivers easy starts and fast drilling Show as "Type B" tip icon on packaging Hole in flute for easy wire pulling through walls, ceilings and floors 3-flatted shank prevents slipping in drill chuck and includes hole for wire pulling Tapered flute for faster chip ejection, less binding and smoother drilling Does not apply to 1/4" diameter SKUs Premium high carbon steel construction for extended drilling life in wood