1,hardness:63-66hrc 2,grade:G10/G16/G20/G24/G28/G40/G60/G100/G200 3,size:2mm-60m Bearing steel ball Production nameG28 ... RangeGauge Interval(μm)Preferred Gauge(μm)101/16”~1”1-10,…..,-1,0,+1,…..,+9281/16”~1”2.00-12,…..,-2,0,+2,…..,+12401/16 ... ,nipples,sliding,blocks,toys.Any further Information,Plz contact us! AISI 52100 bearing steel balls