MICROSTRUCTURE: Microstructure shall be free from continuous carbide network. HEAT TREATMENT: The grinding media is suitably heat treated to obtain the required hardness and Microstructure. STANDARD SIZE OF GRINDING MEDIA:Balls diameter (mm) 125,100,90,80,75,70,65,60,50,40,30,25, & 20 Specifications 1) Diameters Dia. 20 - 150mm 2) Hardness HRC 55-65 3)Impact value >12 J/cm2 4)Breakage rate <0.5% 5）Chemical elements: C:0.60-0.68 Si:0.20-0.40 Mn:0.9-1.3 S,P<0.030 Cr:1.0-1.3 Chemical elements: C:0.57-0.65 Si:0.17-0.37 Mn:0.7-1.0 S,P<0.035 Cr 0.25Max 6)delivery time: normally in 10-30 days