Our mini ball mills are perfect for piloting regrind appliions or ultra low capacity mineral processing test plants. Sizes 8″ x 8″ to 12″ x 24″ (ball and rod mill) Mild steel construction Flanged heads Bronze trunnion bearings (oillubried) Replaceable trunnion liners Replaceable onepiece steel liner with integral lifters Vbelt drive OSHAtype drive guard Modular frame .