Designation:D1578−93(Reapproved2022)StandardTestMethodforBreakingStrengthofYarninSkeinForm1ThisstandardisissuedunderthefixeddesignationD1578;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethodcoversthedeterminationofthebreak-ingstrengthofyarninskeinform.Theobservedbreakingstrengthisexpressedinunitsofforce,andequationsareprovidedtoconvertbreakingstrengthtoskeinbreakingtenac-ityandtoskeinbreakfactor.NOTE1—Forthedeterminationofthebreakingstrengthandelongationofyarnbythesinglestrandmethod,refertoTestMethodD2256.1.2Thistestmethodisapplicabletospunyarns,eithersingleorplied,composedofanyfiberorblendoffibers,butisnotsuitableforyarnswhichstretchmorethan5%whenthetensionisincreasedfrom2.5to7.5mN/texor0.03to0.08gf/denier.1.3Thistestmethodprovidesthreeoptionsbasedontheperimeterofthereel,thenumberofwrapsintheskein,andthemachinespeedortime-to-break.1.3.1Option1—Eighty,forty,ortwentyturnsona1.50mor1.5-ydreel,brokenat300mm/minor12in./min.1.3.2Option2—Fiftyturnsona1.00mor1-ydreel,brokenat300mm/minor12in./min.1.3.3Option3—Fiftyturnsona1mreel,brokenin20s.NOTE2—Option1isingeneraluseintheUnitedStates,Option2isusedforwoolenyarns,andOption3hasbeenproposedintheInterna-tionalStandardsOrganization(ISO)forinternationaluse.NOTE3—Metricreelsareavailablewith1and1.125mcircumferences.Datafromthetworeelswillbeabout1%different(see5.6).ISOusesa1mcircumferencereel.1.4Thistestmethodisfrequentlycombinedwiththedeterminationoflineardensitycarriedoutonthesameskeins.Specialprecautionsforreelingsuchskeinsarenoted.1.5Whereappropriate,thistestmethodstatesallrequire-mentsinSIunits.Thetraditionalunitsareinch-poundandareexactvalues.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associated...
