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(5)RetainerTheroleoftheretaineristokeeptheballsinsidethebearingatevenintervals.Eachmodelhasastandardretainertype,butinsomecasesselectionispossibleinaccordancewiththerequiredperformance.RibbonretainerNMBpartnumber:RJISpartnumber:NosymbolComposedoftwopartsmadeofpress-moldedsteelplates.Atassembly,theballsarearrangedasifclampedbetweentwoparts,withtheclawononepartfoldedontotheotherpart;fixingwithrivetsisalsopossible.GeneralmethodfrequentlyusedCrownretainerNMBpartnumber:HComponentmadeofapress-moldedsteelplate.Thedifferencebetweentheretainer'sinnerandouterdiametercanbedecreased,foruseinultra-thintypeballbearingsorminiatureballbearings.ResinretainerNMB/JISpartnumber:MNComponentmoldedandcutfromresin.ResinsusedincludepolyamidesandpolyacetalamongothersUsedforhigh-speedrotationandlow-noiseapplications33