7/16" 11 MM X 18" LONG LENOX SHIP AUGER DRILL BIT. #31007 Features: Perfectly concentric shape wide flat spiral inside hollow twist design shank indentations for extension bar set screws sharp finely honed cutting edges It is ideal for running pipe or conduit and is great for electricians, plumbers, handy man or gas installers. It has flats on the shank to eliminate the shank spinning in the chuck. The bitS are brand new in retail packaging for use or resale. Any questions please feel free to email us or call us.