... ball1.FORGING STEEL GRINDING BALLS A.SIZE:20-150MM B.HARDNESS:55-65 C.APPLIED FIELD: MINES, CEMENT ... MATERIALS FORGED STEEL BALLS A.SIZE:40-150MM B.HARDNESS:55-65 C.APPLIED FIELD: MINES, CEMENT ... HOT ROLLED STEEL BALLS A.SIZE:30-150MM B.HARDNESS:SIZESURFACE COREPriceDIA30-60MMHRC60-64HRC59-63FOB$700-1000QINGDAODIA70 ... ,P:0.035MAX,S:0.035MAX,CR:0.04 B TYPESIZE:60-90MM,3-6MHARDNESS:45-55CHEMICALELEMENTS:C ...