Designation:B279−13StandardTestMethodforStiffnessofBareSoftSquareandRectangularCopperandAluminumWireforMagnetWireFabrication1ThisstandardisissuedunderthefixeddesignationB279;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethod,knownasthelow-stresselongation(LSE)test,coverstheprocedurefordeterminingthestiffnessofbaresoftsquareandrectangularcopperandaluminumwireintermsofthepermanentelongationresultingfromtheapplicationofatensilestress.1.2TheSIvaluesforthemassofthespecimenareregardedasthestandard.Forallotherproperties,theinch-poundvaluesaretoberegardedasstandardandtheSIunitsmaybeapproximate.2.ReferencedDocuments2.1Thefollowingdocumentformsapartofthistestmethodtotheextentreferencedherein:2.2ASTMStandards:2E4PracticesforForceVerificationofTestingMachines3.SignificanceandUse3.1Thistestmethodisdesignedasaninspectionoraccep-tancetestofnewbaresoftsquareandrectangularwireintendedforsubsequentfabricationintomagnetwire.NOTE1—Sincetheappliedunitstressandthetimeofapplicationareconstantforallwiresizes,thetestenablescomparisonsofstiffnesstobemadebetweenwiresofthesameordifferentsizeonthebasisofthepermanentelongationresultingfromtheapplicationofalowunitstress.4.Apparatus4.1Tensiletestingmachinesusedforthelow-stresselonga-tiontestshallconformtotherequirementsofPracticesE4.5.TestSpecimens5.1Thetestspecimensshallbetakenfromthefinishedreelorcoilwithaminimumamountofhandlinganddistortion,retainingtheoriginalcurvatureofthepackagetothegreatestextentpossible.Testspecimenshavingthefullcross-sectionalareaofthewireshallbeused.Thestandardgagelengthforthemeasurementofelongationofwireshallbe10in.(254mm).Thetotallengthofthespecimensshallbeatleastequaltothegagelengthplusthelengthofwirerequiredforthefulluseofthegripsemployed.6.Procedure6.1Straightenthetestspecimenscareful...
