Designation:B731−96(Reapproved2012)StandardSpecificationfor60%Palladium-40%SilverElectricalContactMaterial1ThisstandardisissuedunderthefixeddesignationB731;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope1.1Thisspecificationcovers60%palladium-40%silverrod,wire,strip,andsheetmaterialforelectricalcontacts.1.2Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.ItistheresponsibilityoftheuserofthisstandardtobecomefamiliarwithallhazardsincludingthoseidentifiedintheappropriateMaterialSafetyDataSheet(MSDS)forthisproduct/materialasprovidedbythemanufacturer,toestablishappropriatesafetyandhealthpractices,anddeterminetheapplicabilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2B476SpecificationforGeneralRequirementsforWroughtPreciousMetalElectricalContactMaterials3.Manufacture3.1Rawmaterialsshallbeofsuchqualityandpuritythatthefinishedproductwillhavethepropertiesandcharacteristicsprescribedinthisspecification.3.2Thematerialshallbefinishedbysuchoperations(coldworking,heattreating,annealing,turning,grinding,orpick-ling)asarerequiredtoproducetheprescribedproperties.4.ChemicalRequirements4.1MaterialproducedunderthisspecificationshallmeettherequirementsforchemicalcompositionprescribedinTable1,inaccordancewiththepracticesprescribedinSpecificationB4764.2Uniformityofcompositionshallbeassuredbytheuseofgoodcommercialpreparationpractices.5.MechanicalRequirements5.1Thecontractorordermayspecifyultimatetensilestrength,elongation,microhardness(KnooporVickers),oracombinat...
