... series, 6900 series, etc.2.Angular contact ball bearing: 7100series, 7200series, 7300series, 7400series, etc.3.Taper roller bearing: 30000series, 31000series, 32000series, 33000 series4.Spherical ... , UCF series, UCFL series7.Self aligning ball bearing: 1200series, 1300series, 2200series, 2300series Ring MaterialChrome Steel ,Carbon steel,Stainless steel,CeramicTolerance gradeGB/T307.1-205ID Size5mm ...