,It'rlEnt^troio trAOt ;Cn rlA io@AnoINTERNANONAL
STANOABDISOG35.2|SO/TC.60Secretariat:ANS|1$o$22oo
notilaTEaanorrocrcilrlJ!^noiC-l.olo d.il* r ,. .' i .J' car io u\
ie"fle . i t in (\r i c c-,e c\e- r'^ro'l *!i "\icoi c\\
iGalculationof load capacity of spur and helicalgears
-Part5:Strengrthand quality of materiatsltc1tt!e- ca9acit de
chargedesengrenagescylindrques dermtrectroite et hticoctate -Patie
5:8srance et qualit des
matiauUDC621.833.1:20.169.1Descriptors:gears! rylindrical gears,
spur gears, helical getus,load
capacity,meterialsspecifications,quality,
tests,determination,cturability.THIS DOCUMENT F A
OfiAFTCIRCULATEOFORCOMMENTANDAPPROVAI-ITIS
THEFEFORESUBJECTTOCI{ANGEANO IIAYNOT BEFEFERBEDTO
ASANINTER1..|ATIOI.|ALSTAI\OAROUNRLPUBTISHEDASStJCH.N ADDmoNTO
THEIR 1ALUATIONASBEINGACCmABLE FOR|NOUSTR|ALTECHNOLOGIC^L
coMMERCtALANDUSEBPURPOSES,DFAFIINTEFI.{AOML
STANDARO6MAYONOCCASIONl{qvETO BECONSIOEBEDtN THEUGHToFTHEIR
PorEt{nrLTo EEcoMEsrANDARosTo wHlcHREFEFENOEMAYBE irADEtNroer-
geeuuroNs.o lntemationalOrganizationforStandardation,1995ISO
635.2:10os(E)Contents1ScopeNormative referencesSymbolsMethods for
the determnationof ailowabte stress
numbersMethodAMethodBMethodBkMethodBpStandardallowablestress
numbers- methodBApplicationPage2344.14.24.34.45I12d oreGraphsfor ,
and o, [m ild
dFE44444556678s.15.2s.3s.3.15.3.25.3.35.466.16.26.216.226.2.36.3Requlrements
for materialquality and heat-treatmentGeneralaspectsMatedal qualtty
and heattreatmentrequirementsStructuralor castleel, plaincarbon,
unalloyedsteelsBlackmalleablecastironOthermaterials,Coupon18181818181830Annex
A: considerations of the slze of the controlling sectionfor
throughhardenedgearing4.1Purpose\2DefinitionA3llluslrations4.4RecommendationsASGeneralcommentsAnnexB:
CertificatesWorkscertcateWorks
testcertifcdeAcceptancetesilcerticdeAnnexC: Table of
hardnessconversionsAnnexD: Testingsurfacehardnesswith a
fileD.1ApplicationD.2DescriptionD.3EquipmentO.3.1
FilesD.3.2ProversD.4TestingAnnexE: BibliographyISO 6335.2:
1995@3r3131313232344g43srtO3636\t363637388.18.28.3ISO63ites:l99s(E)lnlroductionAllowablestressnumbers,as
correredby ths partof ISO6336,mey vary widely.Srch
variatknbtdbutableto clefectsand variationsof: chemicalcomposition
(ctrarge), structure!thetypeandextert of hot working(e.9.,bar
stock, forgng,reduclion raio), trea tretme4residualstresslevels,
eti.Tablessummarize themost mportantinfluerrcingvariablesand the
requirementsforthedifferertmderialsandqualitygrades.Theeffects of
these irfluences on sudacedurabilityandtoothbendingstrengthare
illustratedby the graphs in figures 1 to 14.This pan of lsO 6336
c-oversthe most widely usedgear steels end
relatedheat-treatmertprocesses. Recommendalonson the choice of
specific mderieb,heat-treatmentprocessesormanufacturingprocesses
arenot included.Furthermore,no
commentseremadeconcemngthesuitability,or otherwise,of anymaterials
for specificmanufacturingor
heat-treatmentprocesses.INTERNANONALSTANDARDISO 3es:
lsss(E)calculation of load capacityof spur and helical gears
-Pat5:Strength and quality of materialResr ch,' e T,Jlt. .\u\ n
,otria\_1ScopeThis part of lso
6336describescontactandtooth-roottresses,as
wellasnumericalvatuesforboth limit stressnumbers.Requirementsfor
material gualityand hedtreatmentare specified, together
withcommentsontheir influenceson boh limtsressnumbers.Valuesin
accordancewith ths part of ISOproceduresprwided in ISO ge2and lS
dustriat,HighSpeedand Marine Gears.Theyare alsos 1OOfor rngthe
loadcapacityof banelgears.rackprofiles,profileTheresultsare in
goodof ISO6331.2NormativereferencesThefollowingstandards
containprwisions which,throughreferencein ths
text,constituteprorisons of thispartd lso 6336. At the time of
publition, th editonsnclicdedwere valid.Ailon, and paftes to
aTangementsbasedon ths part o lso 6336arepossibility of applyingthe
mostrecentedition c the standardsIECand lso maintainregstersof
cunently naridrntemaionarStandards.ISO53: 1974, Cylindricalgears
for generaland hearry engineerng- Basic rackSteel-Hardenabititytes
by
endquenchng(Jominytest))oo(ISO68311:1987,Heanreaablestels,alloysteelsandfree{uttngsteels-
pert
11:wrougtrtcase-hardeningsteels)()G)oo(KISO642:1979,ISO64l:19q,ISO
2639:1!)ocISO 4967:19s,ISO 3452: 19o6Maximumlndicdion1,6mm2,43l1
Prlor iructurc QtcnchcdndlcmpcrodOvcdrcding,pcilly dthc
foolipeTovoiri Sicl anoidancc(< 1000.C|12NOTE - Thictblc .ppl..
tolpn typcwith hsdcncdro, hardrrsspdor1)franc hdcningor apinand
todrtetoortypcinductionhardcningimila togurcc 16 rrrd17.Thchardno
Pd.m, dcpth,lacititicsrnd proccrcodmstbc c.tblhcd,documcrtcdand
ctcckcdlo bc rcpcdable.A rcprcntativc..nrplc,withttrcmc Aomr&y
rndmderil thc vortpiecc,muc b. us.d to qudifythcproccss.
Theptoor..rquittcttl and ndrods muctb.
suficbnyrccurd.toproduccthccpccicdcsuhs.Thctddrp6cm muctqtend
tltcllLr{,t olthelcoth andovurllre full profilc,bor f,nk,bo robnd
ba oot fillet.Nocrackr, bsgts, tm. or lpcrrc Frmitted in thc toorrs
of finihcdgcrn,rcgardlan of gradc, Umits:mximum clonc
lrrdicdionpcr25mmollacc widrend maximumof fvc inono too,r nn
Xodicdo..l-loridbolo tE of wo*ingdcpt of to 8;I ground dtcr
niriding,chcc& pingloadcrprcity.l1 Corc:o" Notverificd s >
900tVmm2 n gencral,s96)pcrc.ntg. ollcnitc l than12 Mrnulecfurinq
accuroy,Alter nibidngGroundonty inrpccid ccs;bo waryol possible
reduclionofsudacc bad capacity.29ISO 6336-s2:199s(Qtble ? 'Through
hardenedand case hardeningsteels,bathor gas
ntro+arburizecl(seeligures13 and141r06.3CouponA coupons a testpiece
mactefrom a representativealloygradeof steel. lt maybe
forgedseparately.lt shallaccompanytheproductthrough all
hetreatmentstages.ne test couponshoulct be chosen primarily to
monitorthe qualityof the heat treatmentprocess in terms of
carbonpenetraton and microstructure.An optioncan alsobe takento
usea coupon which representsthepropertiesoftheworkpiece.The
properties of a standardizedcouponmaybe extrapotatedbyexperienceto
estmatethe properties of the wo < piecewith regarct to caseOptn
anOmicrostructure.Details of the manufactureofthe couponmay be
subjea to agreementbetweenthe supplier anctthecustomer.Two types of
couponsare recognized:a) Processcontrollest bars: May be of
arryalloyand shape. Theyareusedto verifylheconsstencyof the heat
treatment process. Theirmicrostructuredoes not
representthemcrostructureof the finished gear,butit maybe
ertrapolated to estimatethecondition ofthefinishedgear,
Suchextrapolationmust be documented.b) Representatlvetest
bars:Aredesignedto representthe quenching rate of thefinished
part.The hardnessand mcrostfuctureat the centerof the coupon
approximatesthe of thecore asdesignated in table 4, fines I and 14.
Recommendedproportionsare:Minimumdiameter:6 x moduleMinimumlenEh:
12x moduteThecouponmaterialsto be equivalentto rhe part in
chemistryandhardenability.309Itcm RrquircmcntML MO
ME123456ChcmicdmelyrbMcchaniclproportios.
dtcrhc.t-bar'n.tClcnlincsGrln izcUltronictcclEdertol
forglngrcduciionA in tble 2 (lhrougherdcning ttecls:itemsI to 6)7
Nibo+crqdzcddrolltimcFromltoEhI
Sulacchrdncss8.1Alhyodaccbt)>5HV82 Unalloyed:tcels>
300l-{vPrc{eatmentHardencdndtcmp.rodwithortsudacedecqrburization.Tcmpcdngtemp.raturcis
to qcccd nitridingtmpGrature,Surleccritructurc(whitclaycrfkailcd
inspcction notmndatoryWhitchycr,5 to 30 r/m thick,
Mostlyenitridcs11 Nito-carburizedcqupment:As
bathnitro-oarburizedVcntiltedtitaniumhed-resisling
alloy(inconcf)pot or rninertlinr,lron dissolvcein
thcmottensaltinhibitingthe nitriding procss.Surfachardnessis
measuredpcendicularshould b appropriateforthecasedepth andtothe
surface; valuesmcasu?cdona sectionmaybehigherlhehrdnss.1)The
testloadAnnex A(normAive)considerations of the slzeof the
controllig sectionfor
throughhardenedgearlngA.fPurposcthrougharimumfor gearing,,t
2Deflnltlonscton which hasthgreaest effectnthelocalm Gecton)
wherethe speciedma
