Small Ball Mills Canada. We sell Small Ball Mills from 2′ to 6' (600 mm X 1800 mm) in diameter and as long as 10″ (3000 mm) in length. The mills are manufactured using a flanged mild steel shell, cast heads, overflow discharge, removable man door, spur type ring gear, pinion gear assembly with spherical roller bearings, replaceable roller bronze trunnion bearings, oil lubrication ...