Designation:D4998−13(Reapproved2021)StandardTestMethodforEvaluatingWearCharacteristicsofTractorHydraulicFluids1ThisstandardisissuedunderthefixeddesignationD4998;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisusedtoscreenlubricantsforgearwear.Itisprimarilyapplicabletotractorhydraulicfluidsbutmaybesuitableforotherapplications.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.SpecificwarninginformationisgiveninSections7and9.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D235SpecificationforMineralSpirits(PetroleumSpirits)(HydrocarbonDryCleaningSolvent)(Withdrawn2021)3D323TestMethodforVaporPressureofPetroleumProducts(ReidMethod)D329SpecificationforAcetoneD4175TerminologyRelatingtoPetroleumProducts,LiquidFuels,andLubricants2.2DeutschesInstitutfurNormung(DIN):4DIN17210Part1:TolerancesforSpurGears;TolerancesfortheDeviationofSinglyDeterminedValuesDIN3962CasehardenedSteel;MaterialSpecificationsDIN50150TestingofSteelandCastSteelConversionTableforVickersHardness,BrinellHardness,RockwellHard-nessandTensileStrengthDIN51354MechanicalTestingofGearOilsintheFZGGearTestMachine3.Terminology3.1Definitions:3.1.1abrasivewear,n—wearduetohardparticlesorhardprotuberancesforceda...
