ThreadandEndConnectionIdentificationGuidewww.swagelok.comIDENTIFICATIONTABLESTAPEREDSTRAIGHTAPPENDIXINTRODUCTION3ContentsIntroductionThreadandEndConnectionTerminology....4GeneralTerminology..................5Step-by-StepIdentificationProcedureforThreadsandEndConnections..............6ThreadIdentificationReferenceTables..................12TaperedThreads..................20EndConnectionsThatUse:TaperedThreads.....................22StraightThreads..................26EndConnectionsThatUse:UnifiedScrewThreads.................28ISO228/1Threads...................35Metric(ISO261)Threads..............42NPSMThreads......................49AppendixEndConnectiontoThreadMatrix........50ThreadtoEndConnectionMatrix........51ThreadIdentificationTools.............52Glossary...........................534INTRODUCTIONIntroductionThreadandEndConnectionTerminologyStandardsareusedtohelpidentifythreadsandendconnections.Wewillusethefollowingdefinitionsinthismanual:ThreadStandardAspecificreferencetoaformalstandard(forexample,ANSI/ASMEB1.1,DIN2999,orISO261)whichdescribesthreadform,includingathread’sangle,pitch,anddiameter.EndConnectionStandardAspecificreferencetoanationalstandard(suchasDIN3852orJISPT)orindustry-groupstandard(suchasSAEJ512)whichdescribesanendconnection’scomponents,sealarea,geometry,andnominalsizes.Threadstandardsareusuallyreferencedintheendconnectionstandard.ThreadStandardsandEndConnectionStandardsManymechanicalendconnectionshavethreads.Therefore,threadstandardscanbeusedtohelpdefineendconnectionstandards.PitchForthepurposesofthisguide,pitchreferstothreadsperinch,insteadofthedistancebetweenthethreads,forfractionalscrewthreadsandpipethreads.Forallmetricscrewthreads,pitchreferstothedistancebetweenadjacentthreads.5INTRODUCTIONGeneralTerminologyGeneraltermsandcharacteristics,whichapplytoallendconnectionthreads,areshownbelowforbothmaleandfemalethreads.Threads1.Crest5.ThreadFlankAngle2.Root6.TaperAngle3.Flank7.MaleThreadOD4.Pitch(Metric)8.FemaleThreadIDEndConnections1.BodySize2.Shoulder3.FaceMaleFemaleEndConnection123512346786IDENTIFICATIONStep-by-StepIdentificationProcedureforThreadsandEndConnectionsSTEP1:Determineifthethreadistaperedorstraight(parallel).STEP2:Measurethethreaddiameter.STEP3:Determinethethreadpitch.STEP4:Determinethethreadstandard.STEP5:Identifytheendconnection.NOTE:Evenexperiencedworkerssometimeshavedifficultyidentifyingthreads,regardlessoftheirthreadidentificationprocedureandthequalityoftheirgauges.DetailsSTEP1:Determineifthethreadistaperedorstraight(parallel).Useacalipertomeasurethenominalmaleorfemalethreadcrest-to-crestdiameteronthefirst,fourth,andlastfullthreads.(SeeFigure1.)Ifthediametersincreaseforamaleendordecreaseforafemaleend,thethreadistapered.Ifallthediametersarethesame,thethreadisSTSTFigure1.MeasuringCrest-to-CrestThreadDiametersLast4th1st7IDENTIFICATIONTSstraight(parallel).STEP2:Measurethethreaddiameter.Useacalipertomeasurethenominalmaleorfemalethreaddiameterfromcrest-to-crest.(SeeFigure2.)Measurethefourthorfifthfullthread.Measureanyfullthread.Thediametermeasurementobtainedinthisstepmaynotbeexactlythesameasthelistednominalsizeforthegiventhread.Themainreasonforthisvariationisindustryormanufacturingtolerances.STEP3:Determinethethreadpitch.Todeterminethethreadpitch,usetheSwagelokpitchgaugesandcheckthethreadagainsteachformuntilyoufindamatch.Ifyouprefertonarrow...
