Grinding Media Grinding ball Grinding Media1) Chrome steel grinding balls; AISI52100 Chrome steel, through hardness 62-65 rockwell '' C'' ,super-fine ... surface ,available 2mm to 25.4mm2) Carbon steel grinding balls: AISI1018 Case hardened , AISI 1085 through hardened, AISI1065 ... fine surface available, 0.5mm to 25.4mm3) Stainless steel grinding balls: AISI302, 304, 316,420,440 , Super-fine ...