Visually, the import Ball Mill has rough surface, white coloring when cut off, and small cracks at all specimens. Type A ball mill contains of 2,934% C, 11,231% Cr, and 0,177% Mo, where type B Ball Mill contains of 2,693% C, 12,31% Cr, and 1,103% Mo. Both are martensitic white cast iron ASTM A532 Class II type A.