- 4 x 3 ft Marcy skid mounted ball mill, - Made in USA, - Refurbished mill, - Internal grate before discharge, - Bolt on feed and discharge heads, - Bull gear with guard, ... Get email updates for newly added Grinding Mills - Ball, Pebble, Sag, Mining. New Listing Alert. 4' x 5' Denver, Ball Mill, 37' diameter Sheave, rubber lined, 2-pc bull gear.Web