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 Raw material 45# steel,60Mn,50Mn,RCAB-1,RCAB-2,RCAB-6 STANDARD SIZE OF GRINDING MEDIA:Balls diameter (mm) 150mm,140mm,130mm,125mm,100mm,90mm,80mm,75mm,70mm,65mm,60mm,50mm,40mm,30mm,25mm, 20mm TOLERANCE ON SIZE: Variation on size shall not exceed the following limits SHAPE AND SIZE TOLERANCE (mm) Balls for sizes 90mm & above +3.0/-1.5 Balls for sizes 60 mm to 90mm + 2.50/-1.0 Balls for sizes 30 to 50 mm & below + 2.00/-1.0 Balls for sizes 15 to 25 mm & below +1.0/-0.5