DIN7500-三有机械牙规范

SpecificationNo.5ThreadRollingScrewsacc.toDIN7500-12009Page1of11Editor:VHMDate:02.02.1989Release:02.02.1989implemented:02.02.1989Revision:ABCDEFEditor:VHMSPSSPSSPSSPSVWIPage:allallallallallallreleased:22.07.9630.08.9727.10.9706.01.984.01.0111.08.10implemented:22.07.9601.09.9727.10.9706.01.984.01.0111.08.10Agreementbetween:BossardAGSteinhauserstrasse70PostfachCH-6301Zug(hereaftercalledBossard)and(hereaftercalledSupplier)Rev:FSpecificationNo.5Page2of11TableofContentsPage1.Introduction32.Manufacturing32.1Material32.2CaseDepth32.3CaseHardness32.4CoreHardness32.5Plating33.InspectionTests53.1TorsionalTest53.2BendingTest63.3DriveabilityTest73.4HydrogenEmbrittlementTest84.Certification105.Annex:Inspection-TestForm11Rev:FSpecificationNo.5Page3of111.IntroductionTheSpecificationNo.5isprimarilybasedonDIN7500-1.TherevisionofthisdocumentgenerallywillbeupdatedaccordingtotheDIN7500-1updates.However,thediscretionofthisdocumentwillbedeterminedbytheownerofthisdocument.AllrequirementsspecifiedinDIN7500-1shallbemetwithoutconcessions.SpecificationNo.5isarestrictionofcertainparametersandaddsadditionaltests.Remarks:TheupdateofthisdocumentatRevFisbasedonDIN7500-1:2009-062.Manufacturing2.1Materialacc.toDIN7500-1:2009-06Coldheading,casehardeningqualitysteelasspecifiedinDIN7500-1:2009-06.2.2CaseDepthacc.toDIN7500-1:2009-06Thecasedepthisthedistancemeasuredfromthesurfacetothepointwherethehardnessis400HV0.3NominalDiameterCaseDepth(mm)M2andM2,5M3andM3,5M4andM5M6andM8M10andM120,05to0,150,07to0,180,10to0,250,15to0,280,18to0,322.3CaseHardnessThecasehardnessshallbeminimum450HV0.3andmaximum560HV0.32.4CoreHardnessacc.toDIN7500-1:2009-06Thecorehardnessshallbe290-370HV10Ford4mmthecorehardnessshallbe290-370HV52.5PlatingThedurationofthepicklingprocessshallbeontheveryminimum.Zincplatingthickness3-5μm.Onverylongscrews(l≥15xthreaddiameter)theplatingthicknessontheheadtopsurfaceshallnotexceed12μm.Otherwisetherecouldbeanincreasedriskforhydrogenembrittlement.Inthiscasemin2μmplatingthicknessareacceptableinthemiddleoftheshank.Rev:FSpecificationNo.5Page4of11Acc.toISO4042(1999)thepartsshouldbebakedwithin4hours,preferablywithin1hourafterelectroplatingandbeforechromatingtoaparttemperatureof200°Cto230°C.Bakingduration4-6hours.Thehydrogenembrittlementtestrequirementsmustbefulfilled–seechapter3.5.Finallythescrewshavetobewaxed(invisible,drytotouch).Rev:FSpecificationNo.5Page5of113.InspectionTests3.1TorsionalTestacc.toDIN7500-1:2009-06nominaldiametermin.breakingtor-que(Nm)M2M2,5M3M3,5M4M5M6M8M10M120,41,01,82,84,18,715,037,075,0133,0Samplesizepermanufacturinglot:min.8screwsRev:FSpecificationNo.5Page6of113.2BendingTestThescrewsshallbeclampedinavicewheretheclampedlengthisapprox.2xnominaldiameter.Seedrawing.Bymeansofminimum6gentlehammerstrokes,thescrewsshallbebentminimum30°.Testevaluation:2xd1min.30°d1Samplesizepermanufacturinglot:min.8screws.Thetestrequirementsarefulfilled,ifallscrewscanbebentdownwithoutabrittlebreakinginto2separatepieces.Inthebendingareaacrackwithadepthofmaximum2/3threaddiameterisacceptable.Rev:FSpecificationNo.5Page7of113.3DriveabilityTestacc.toDIN7500-1:2009-06Thefinished,waxedsamplescrewsshallbedrivenintoatestplate.Thetestplateshallbeoflowcarbonsteel(max.0.23%C)havingahardnessof115-135HV30.Theholediametersshallbeasgiveninthetablebelow:nominaldiameterplatethickness(mm)holediameter(H9)(mm)max.drivetorque(Nm)M2M2,5M3M3,5M4M5M6M8M10M122,02,53,03,54,05,06,08,010,012,01,8to1,8252,3to2,3252,75to2,7753,2to3,233,65to3,684,6to4,635,5to5,537,4to7,4369,3to9,33611,2to11,2430,30,61,01,62,44,78,020,039,070,0Afterthistest,thethreadcrestsshallnotbedeformed!Samplesizepermanufacturinglot:min.8screws.nichtOKOKnichtOKnotokoknotokRev:FSpecificationNo.5Page8of113.4HydrogenEmbrittlementTest–similartoISO15330(1999)Thefastenerstobetestedmustbeinthefinal,platedandwaxedcondition.Thetesthastobestartedmax.24hoursaftertheplatingprocess.Thetesttemperatureisambienttemperature.Testapparatus:Theapparatuscomprisesatestplateandaspacer.a)TestplatePlatemadefromsteelwithpretapped,threadedholes.Thicknessoftheplateismin.1xnominaldiameterofthetestscrew.b)SpacerToachievepreloadaftertightening,aspacermustbeplacedunderneaththescrewhead.dAbstandshülseThethroughholediameterinthespacer(bushing)shallbeinaccordancewithISO273,mediumseries.Nominaldiameterthroughholediameter(mm)M2M2,5M3M3,5M4M5M6M8M10M122,4-2,542,9-3,043,4-3,583,9-4,084,5-4,685,5-5,686,6-6,829,0-9,2211,0-11,2713,5–13,77Thehardnessofthespacershallbeminimum300HV.Thesurfaceshallbesmooth.Prüfplatte1xdlHSpacerPlateRev:FSpecificationNo.5Page9of11Forscrewswithshanklength≥2,5xnominaldiameter,thelengthlHofthespacershallbemin.1xnominaldiameter.Forscrewswithshanklength2,5xnominaldiametermin.1degreasedspringwasherDIN6796shallbeplacedunderneaththescrewhead.Forcountersunkheadscrewsthesametestconditionsapply.ForpartiallythreadedscrewsthelengthlHofthespacer(s)mustbeadapted.Tighteningtorqueforthehydrogenembrittlementtest:Screwsshallbetightenedattorquewithasuitabletorquewrenchupto90%ofthesmallestvalueofbreakingtorquesdetermined(3.1TorsionalTest)on8sc