... :G500/G1000 ISO qulified company Production name1/4 inch steel ball for bicycle spare partssize1/4",3/16",5/32",1 ... /8",7/32",5/16",7/8",1"GradeG100,G200,G500,G1000,G2000HRC58-62hrcQuality ... /output per yearmore than 5000ton/year 1/4 inch steel ball for bicycle spare parts