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 Our products have obtained ISO 9001 ---2000 International Quality System Authentication and ISO14001--2004 Environmental System Management Authentication. The grinding balls is awarded the famous brand pro-ducts of Shandong province.