Lenox 30888-VB11 Vari-Bit 7/8-Inch to 1-1/8-Inch Step Drill Bit with 3/8-Inch Shank for 1/2-Inch and 3/4-Inch Conduit Accurate, burr-free holes Starts drilling on contact Shank Size (inches): 3/8" Steam oxide coating adds durability Two flute design cuts fast, clean round holes