Solid augers have a hex shank (pin) up and a hex socket (box) down. The standard length is 5' with other length sections available. All Mills Machine built solid augers have hard surface coating on the outer flighting edge. *Solid Auger diameters are designated by the hole diameter cut by the solid auger cutter head. The actual diameter of the auger is smaller so the auger flighting conveys the cuttings and the cutter head does the work. See 'Auger Diameter' column above for actual diameter of the auger.