Designation:F2489−06(Reapproved2013)StandardGuideforInstrumentandPrecisionBearingLubricants—Part2Greases1ThisstandardisissuedunderthefixeddesignationF2489;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisguideisatooltoaidinthechoiceoflubricatinggreaseforprecisionrollingelementbearingapplications.TherecommendationsinthisguidearenotintendedforgeneralpurposebearingapplicationsTherearetwoareaswherethisguideshouldhavethegreatestimpact:(1)whenlubricatinggreaseisbeingchosenforanewbearingapplicationand(2)whengreaseforabearinghastobereplacedbecausetheoriginalgreasespecifiedforthebearingcannolongerbeobtained.TheReport(seeSection5)containsaseriesoftestsonawidevarietyofgreasescommonlyusedinbearingapplicationstoallowcomparisonsofthosepropertiesofthegreasethatthecommitteethoughttobemostimportantwhenmakingachoiceoflubricatinggrease.Eachtestwasperformedbythesamelaboratory.Thisguidecontainsalistingofthepropertiesofgreasesbybaseoiltype,thatis,ester,perfluo-ropolyether(PFPE),polyalphaolefin(PAO),andsoforth.Thisorganizationisnecessarysincetheoperationalrequirementsinaparticularbearingapplicationmaylimitthechoiceofgreasetoaparticularbaseoiltypeandthickenerduetoitstemperaturestability,viscosityindexortemperature-vaporpressurecharacteristics,etc.Theguideprovidesdatatoassisttheuserinselectingreplacementgreasesforthosegreasestestedthatarenolongeravailable.Theguidealsoincludesaglossaryoftermsusedindescribing/discussingthelubricationofprecisionandinstrumentbearings.1.2Thelubricatinggreasespresentedinthisguidearecommonlyusedinprecisionrollingelementbearings(PREB).ThesegreaseswereselectedforthetestingbasedonthegreasesurveyobtainedfromDoD,OEMandgreasemanufacturesandevaluatedaccordingtothetestprotocolthatwasdesignedbySubcommitteeF34onTribology.Thistestprotocolcoverstheessen...