... -66hrc 2,grade:G10/G16/G20/G24/G28/G40/G60/G100/G200 3,size:2mm-60m Bearing steel ball Production nameG28 ... ,G40,G100-G1000 high precision bearing steel balls size2MM-60MMGradeG28,G40,G80 ... ,G100,G200,G500,G1000,G2000HRC58-62hrcQuality certificateISO 9001:2008/SGS test ...