Designation:D6272−17StandardTestMethodforFlexuralPropertiesofUnreinforcedandReinforcedPlasticsandElectricalInsulatingMaterialsbyFour-PointBending1ThisstandardisissuedunderthefixeddesignationD6272;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationofflexuralpropertiesofunreinforcedandreinforcedplastics,includinghigh-moduluscompositesandelectricalinsulatingmaterialsintheformofrectangularbarsmoldeddirectlyorcutfromsheets,plates,ormoldedshapes.Thesetestmethodsaregenerallyapplicabletorigidandsemirigidmaterials.However,flexuralstrengthcannotbedeterminedforthosematerialsthatdonotbreakorthatdonotfailintheouterfibers.Thistestmethodutilizesafourpointloadingsystemappliedtoasimplysupportedbeam.1.2Thistestmethoddescribestwoprocedures(ProcedureAandProcedureB),theselectionofwhichdependsonthebehaviorofthesampletobetestedasexplainedbelow:1.2.1ProcedureA,designedprincipallyformaterialsthatbreakatcomparativelysmalldeflections.Itshallbeusedformeasurementofflexuralproperties,particularlyflexuralmodulus,unlessthematerialspecificationstatesotherwise.1.2.2ProcedureB,designedparticularlyforthosematerialsthatundergolargedeflectionsduringtesting.Itissuitableformeasurementofflexuralstrength.1.3Comparativetestsarepermittedtoberunaccordingtoeitherprocedure,providedthattheprocedureisfoundsatisfac-toryforthematerialbeingtested.1.4ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesprovidedinparenthesesareforinforma-tiononly.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.NOTE1—ThistestmethodissimilartoISO14125,MethodB.However,ISO14125,MethodBsp...
