Designation:D3702−94(Reapproved2014)StandardTestMethodforWearRateandCoefficientofFrictionofMaterialsinSelf-LubricatedRubbingContactUsingaThrustWasherTestingMachine1ThisstandardisissuedunderthefixeddesignationD3702;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofwearrateandcoefficientoffrictionforself-lubricatedmaterialsinrubbingcontactbyatestingmachine2thatutilizesathrustwasherspecimenconfiguration.NOTE1—Thismachinemayalsobeusedtomeasurecoefficientoffriction.1.2ThevaluesinSIunitsaretoberegardedasthestandard.Incaseswherematerials,products,orequipmentareavailableonlyininch-poundunits,SIvaluesinparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.Terminology2.1Definitions:2.1.1coeffıcientoffriction,µorf—intribology—thedimen-sionlessratioofthefrictionforce(F)betweentwobodiestothenormalforce(N)pressingthesebodiestogether.µorf5~F/N!(1)2.1.1.1Discussion—Adistinctionisoftenmadebetweenstaticcoefficientoffrictionandkineticcoefficientoffriction.2.1.2wear—damagetoasolidsurface,generallyinvolvingprogressivelossofmaterial,duetorelativemotionbetweenthatsurfaceandacontactingsubstanceorsubstances.2.1.3wearrate—therateofmaterialremovalordimen-sionalchangeduetowearperunitofexposureparameter;forexample,quantityofmaterialremoved(mass,volume,thick-ness)inunitdistanceofslidingorunittime.2.2DefinitionsofTermsSpecifictoThisStandard:2.2.1torque—reactionofatendencytoturnduetofrictionforcesbetweenspecimenstravelinginacircularpath.Itistheproductofarestrainingforceandtheradiusatwhichitactstobalancethefrictiona...
