DIN-267-24-1983-ENG

UDC621.882.3-034.14/.15:539.4:620.17DEUTSCHENORMAugust1983FastenersTechnicaldeliveryconditionsPropertyclassesfornuts(Hardnessclasses)-DIN267Part24MechanischeVerbindungselemente;technischeLieferbedingungen;FestigkeitsklassenfürMuttern(Härteklassen)ThisStandard,togetherwithDINIS0898Part2,March1981edition,andDIN267Part21,June1981edition,supersedesDIN267Part4,October1971edition,andDIN267Part8,October1971editionwithdrawnin1981.InkeepingwithcurrentpracticeinstandardspublishedbytheInternationalOrganizationforStandardizationflSO),acommahasbeenusedthroughoutasthedecimalmarker.DIN267Part4wasconvertedtotheinternationalpropertyclassesfornutsin1967.Theprevioussymbols4D.5D.5S,6G,6sand8Gwerereplacedbycodenumbers4,5,6,8,IO,12and14,wherethecodenumberindicated1/100oftheminimumtensilestrengthoftheboltwithwhichthenutcouldbematedandloadeduptotheminimumtensilestrengthofthebolt,e.g.bolt10.9-nutIO.Appropriateproofloadvalueswereallocatedtothenuts.Afterrelevantstudies,experimentsandcalculations,thissystemofpropertyclasseswasmodifiedattheinternationallevelandlaiddowninInternationalStandardIS0898Part2(seeDINIS0898Part2)inanimprovedversionandwithgreatercertaintyregardingtighteningandtheloadabilityofbolthutassemblies.ComprehensiveexplanatorynotesareincludedintheNationalforewordandAppendixtoDINIS0898Part2.Thisalsoexplainsthattheprevi-ouslyusualhexagonnutswiththenominal0,8dnutheight(e.g.nutscomplyingwithDIN934)cannotbefullyloadedwithsufficientassuranceuptotheyieldpointoftheappropriateboltorbeyondthis,withoutthenutbeingstripped.HigherproofloadvalueshavebeenallocatedtotherevisedpropertyclassesinDINIS0898Part2,inordertoensurethatfracturegenerallyoccursinthecaseofoverloading,inaccordancewiththeusualprinciplesofdesign.ItwasoriginallyintendedtodeletethepreviousspecificationsforpropertyclassesfornutswithcoarsethreadsfromDIN267Part4,toreplacethesebyareferencetoDINIS0898Part2,andonlytospecifyinDIN267Part4thepro-pertyclassesfornutswithfinethreadswhichhavenotbeenspecifiedattheinternationallevel.Itwasnecessarytoabandonthisproposal,sincenotonlyhigherproofloadvaluesareassignedtotheIS0propertyclasses,butthesepropertyclassesalsorequirelargernutheightsinsomecases(seeDIN970,forexample).Therefore,inconsiderationofexistingstandardswhichcannotbesupersededintheshortterm(e.g.DIN934)andofnumerousotherdocumentsanddrawings,DIN267Part4wasretainedforanasyetunlimitedperiodspecifyingthepreviousproofloadvalueswhicharelowerincomparisonwithDINIS0898Part2.However,becauseDINIS0898Part2specifiestheinter-nationalcodenumbers,ithasbecomenecessarytoaddtwoverticalbarstothecodenumbersinDIN267Part4,inordertodifferentiateproductscomplyingwiththetwostandards,e.g.181insteadof8,sothattheremaybenocon-fusioninthefuture.BywayofsupplementtoDINIS0898Part2,DIN267Part23liststhepropertyclasses(IS0classes)fornutswithfinethread,calculatedonthebasisofthisstandard.Furthermore,thepropertyclassesfornutswithoutdefinedproofloadvalues(hardnessclasses)havebeentakenfromDIN267Part4andhavebeenspecifiedinDIN267Part24.Thus,atpresent,therearethefollowingstandardsdealingwithpropertyclassesfornuts:DINIS0898Part2Mechanicalpropertiesoffasteners;nutswithspecifiedproofloadvaluesDIN267Part4Fasteners;technicaldeliveryconditions;propertyclassesfornuts(previousclasses)DIN267Part23Fasteners;technicaldeliveryconditions;propertyclassesfornutswithfinethread(IS0classes)DIN267Part24Fasteners;technicaldeliveryconditions;propertyclassesfornuts(hardnessclasses)ThisdivisionprovidesaclearseparationbetweenthepreviousDINpropertyclassesandthenewIS0classes.Itpermitsacorrespondinglysimilarseparationinproductstandardsandpreventsincorrectallocation(seealsotheExplanatorynotes).Continuedonpages2to4EeuthVerlagGmbH.Berlin30.hasexclusivesalerightsforGermanStandards(DIN-Normen)DIN267Part24Engl.PricegroupISalesNo.010502.85Page2DIN267Part2411H.14H.17H1FieldofapplicationThisstandardspecifiesthemechanicalpropertiesofnutswhichdonothavetowithstandspecifiedproofloads.Thepropertyclassesspecifiedhavebeenclassifiedaccordingtominimumhardnessvaluesfromwhichhowevernoconclusionscanbedrawnwithregardtotheloadabilityandthestrippingstrengthofthenuts.Theperformancepropertiesofnutsdependontheirstyle.Thisstandarddoesnotapplyto-nutswhichhavetowithstandspecifiedproofloadsinaccordancewithDINIS0898Part2,DIN267Part4andPart23;-prevailingtorquetypenutsinaccordancewithDIN267Part15;-nutswhichhavetomeetparticularrequirements,forexamplewithregardtoweldability,corrosion-resist-ance(seeDIN267Part1I),abilitytowithstandtem-peraturesabove+3OO0Corbelow-50C(seeDIN267Part13).Note.Nutsmadeoffreecuttingsteelshallnotbeusedattemperaturesabove+250OC.0.500,120,350.342DesignationThepropertyclassesfornutsasspecifiedinthisstandardshallbeidentifiedusingacombinationofanumberandaletterasgivenintable1.Thenumberindicatesl/10oftheminimumVickershardness,theletterHstandsforhardness.Table1.SymbolsBrinellhard-min.nesSHB30max.classPropertysymbolI11H114H117H122HII105133162209176204233285VickershardnessHV5min.1101401703Materials3.1NoncuttingworkingThechemicalcompositionspecifiedintable2shallalsoapplyto