Designation:E1685−13StandardPracticeforMeasuringtheChangeinLengthofFastenersUsingtheUltrasonicPulse-EchoTechnique1ThisstandardisissuedunderthefixeddesignationE1685;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticecoversaprocedureformeasuringchangesinlengthofthreadedfastenersusingconventionalultrasonicpulse-echobolt-measuringinstrumentationwhichhasbeenproperlycalibrated.1.2Thisprocedureisnormallyintendedformetalbolting6.3mmormoreinnominaldiameterwitheffectivelength-to-diameterratiosof2:1orgreater.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E6TerminologyRelatingtoMethodsofMechanicalTestingE1316TerminologyforNondestructiveExaminationsE1544PracticeforConstructionofaSteppedBlockandItsUsetoEstimateErrorsProducedbySpeed-of-SoundMeasurementSystemsforUseonSolids(Withdrawn2012)32.2ASMEStandards:4ASMEB46.1–2009SurfaceTexture(SurfaceRoughness,Waviness,andLay)3.Terminology3.1ThedefinitionsinthispracticeareinaccordancewithTerminologyE6andSectionIofTerminologyE1316.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1changeinlength[L],n—physicalchangeinlengthofathreadedfastenerduetoachangeintensionwithinthefastener.3.2.2effectivelength[L],n—thelengthofaboltthatisresponsivetostress.3.2.2.1Discussion—Thisquantityliessomewherebetweentheoveralllengthoftheboltandthegriplength.Itisusuallyestimatedasthegriplengthplusonehalfthethicknessoftheheadandonehalfthethicknessofthenut.3.2.3longitudinalwave,n—thosewavesinwhichthepar-...
