It is a low- chromium cast steel ball and is available in four different diameters to suit different ball mills. Diameters of grinding ball available range from 50,8 to 88,9 mm. Its surface hardness: 58 – 64 Rc and its volumetric hardness is 58 – 64 Rc. The percentage of Chrome is 0,2 – 0,8. They can be packed and delivered in bulk, in ...