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1 lJis is Ih e fo urth a nd.finl
article in a series 111(ploriI l9
rite lIew IS O 6136 gea rat~
in , stlnd,rd nd its mf1tlJ~
o p in io ns IIx p re ss ed h ere in
.re tiJose' IO fthe authDr . ,a n
. individual . 1 lJBy,donat rep
, msen t he o p .in ions 01 . any
,organizlItionuI which l i e is
member.
ISO 6336-5: Strengthand Quality of Materials
C o m p aris o n o f A G M A .2 0 01 a n d IS O, 6 3 3 6ratingsto r fo ur g ea rsets.
Don McVi tt; ie
Gear rating s ta nd ar ds a re in te nd edto p ro v id e a re li -
able method of com paring gear setc a pa c it ie s. w h e nth es am e sta nd ard is used to c alc ula te e ac h e xa mple ,It
should motsu rp rise usthat. th e sa me gear set h a s a dif-ferent rated capacity when calculated by th e rsOandA G M A standards.Wes'oouJd ,expect, Ilowever, lhal.1he
ratio between ISO rated capacityand A G MA rated
c apa city beapproxim ately rite sam e for,different gear
sets. T h is a rtic le e xa m in esI 1 J ecalculated ral.ingso f fo urgear sets and exploressome possible causes fO rdiffer-e ac es .. Som e diffe re nc es a re dueto a ll ow a bl e m a te ri a]
stress n um be rs a ndsome are due11.00 Iber in:fluence fac-
tors.Tables provide specifics of tile four gear sets an dth e ln flu en ee f ac to rs a cc or din gto each standard.
Classification of Materialsm so, 6336-5contains data fo r a w ide v arie ty o f c ast
a nd w ro ug ht fe rrou s ge ar m ate ria lswith. d if fe re nt h ea t
t rea tment condit ions . Th e material types ar e shown in
Fig. I, w ith the abbreviations assigned to eachtype.
8 1 ~ S ts sl ia e .< 0 00 N lm m2,v Througll-hardeninglsteal, Ihrougfl-hard l1,dla B ~ 0 00 'N /m m2,
GG i=G r ey c a s ' i ro nG6G,(pari.,'bai..ferr.'e N o du la r c as t I ro n I pe rf i1 ic . b ai ni ti c. l er ri li estructure)'
GTS pel l. )= Black manaable, ClSt iron pe:rli t icstructurel'Ell'= CaSl~h_Lrdenlngl Iee . cne hardened'IF = S W el, a nd G G G ,. Ha ms o rind~cllon hardened
IN Tlnittl = Nitrid 'n; stlUl~ nitr idedN V ( n il rJ= Througbh:ardl rung and cl II hardeningSIlIel , nif l id 'ed
N Y(nItroe,r. , = T h ro ug h- ha rd ni ng L n d C U I I I- rd an in g S le e l, n il ro ca rb uf i. ze d: is u ltim al.e ten sile rue ng th . a pp ro xim ate lv 3 .4 B H N , 'N/m m
IF ill> 1 - M . te , i.1r y p -s , in 1 5 0 1 1 & 3 ; 3 & . 5 .
1 1 0 0
lID
9 I X l
8 0 0
.:r 7 0 0E
~ ' 6 0 0J:z : . ' 5 0 0\:)
4 0 0
M X/.1
I II
Alloy Steels V : ,. -M E I I/ / M IlI I '
., I V I '
./ ../ 1
. C a r o l M L
Staal ME
.. . Mil
' Ml ,.', . .
I I
2 0 0 4 0 0
S ui1 aca hardnass IV 1Q (=IIBIN O fE -N om in ll c arb on c onte nt; :0 \ .20 ' J I0 ,
F ig . 2 : - T Jrro ug bhardening ste.ls:tlJlowalll, 1tt811 DUmb 11 ' [contact),20 GE AR T ECH NO lO GV
N ote that rhrough-harden.ing steels softer than
approxim ately 23 5 B HN are classified as car
steels (S o. rather than as through-hardened allo
steels (V) with ,3 reduction in allow able stress numbe rs. C arb uriz ing stee ls a re subd ivid ed in tothree sub-
classes, depending on t1 M de na bility a nd m inim um
core hardness. N ~triding steels are also ubdivi
into se ve ra l su bc la sse s, de pen din g on alloy c on te
E ach m aterial type is s ub div id ed into qUalityg ra de s a cc or din g to the c le anlin ess a ndprocessing
criteria established iln section 6 of t he s ta n da rd . G ra deM L stands forth e m in im u m r eq uir em e nt,
sim ilar to A G MA grade 1 _
G ra de M Q represent .~ ,r eq ,u ir em e n lt s w h ic hca nbe met by experienced manufacturers at m oderac os t, sim ila r to A G M A grade 2. M Q is also th e
d efa ult. m ate ria l g ra defor indust ria l. gears .
Grade ME represents requiremenrs which mustbe realiz ed w hen higher allow able stresses are de
able, sLmilar to A G MA grade3 . . G r a de MX is a special grade of through-bard-
e ne d ste el,with hardeoability selec te d fo rth e criticalsection size.
Although ML, M Q and M Erequsementsarelist-ed for all material types, no t all of these com bine-tions are readily availabl'e in dIe m ark et, A ..D'effort
being m ade to reducetae number of grades fort
: ne x.t ,e ditio n o f I SO ,6 3 3 6 -5 .
Allowable Sha5 NumbersT he ISO 6 33 6-5 standard describes the m eth
used to derive allow able stress numbers from
sca le g ear tests, ( me th od A ), re fe re ee ete t gears or
test specim ens. T he stress numbers represent a
vival rate of 99%,. as 0the AG M A standards. Apresent, W SO 63 36 doesno t offer a specific w ay toc alc ula te r atin gsfor other survival rate '.
A llow able stress num bers for recognized g
material are presented in graphical form. Figureand 3 are exam ples oflltoe graphs.
The allow able stress numbers for pitting a
bending are plotted a ga in st su rfa ce h an l'lIe ss ,which
isexpressed in e ith er B r in ellor Vickers units. H B iused for softer materials, H V 1 0 10 k g load) isused
for m ost through-hardened materials and H V 1 (I
loa d) is used w he re a pp:I'O pria te fo r su sfa ee ha rd en
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aterials. Th e allow abl tre nw nbers for gradeMQ
e comparable 10 tb ose fo rA G M A grade 2 , exce ptfo r
e pitting trength of througb: .. hardened alloy steels.a n y e x pe r ie n ce dmanufacturers of through .. hardenedars w in find that heir products can m eet the require-en ts of gra deJvIX, w hic h h as a llow ab le co nta ct sireS
um be rs c om pa ra ble '1 0 AG M A grade 2. F igure 2
ow s the higherallow able contact tress num bers per-
itted for jhe MX grade of through-hardened alloyee ls , c o m pa re dto ML MQ and M E.
R quirements for Material Quali~yand H at Treatment
A serie .of table definesthe metallurgical r eq uir e . .
ents for each grad. of each m aterial clas . There:i
od general agreement between the ISO and A GM A
quirements for s im ila r m ate ria l and allowable
ress numbers, bul IS O m etallu rgic al q ua fitystan-rds rather than A STM are the reference documents
r IS O sta nda rd s ..Yourteel u pp lie r a nd he at tr ea te rs
ill need to k now the [SO .landard to be sure thate ir w ork c om plie w ith the de taile d re quire me nts.
T here are a few places w here the details of the
easurem ent m ethods and speeificatiens differ. F or
ample. the p ec il'ie d p oin tto measure core hard-
s in a fini hed toothpe r ISO 6 3 3 6 i on e module
low the surface ona lin perpendicularloth 3 00
ngent to the root fille t, rather than on the center ofe tooth on the root diam eter as in A O M A (Fig. 4).
hese djfferences don I affect th e engineer making
ting calculations. but they couldbe of concern in
e at t re a tm e nt comrol and certification.The ISO tandard recognizes proce s con uo te
ars. w hich m ay be any iz e, to m onitorth e c oa si te n-of th e heatireaimem proce an d represeruativf lest
ars w hich are large en ugh to representth e qUllchte of thefinished part, T he m icro tructure of therep-
es e nt at iv e l es t b ar smay b e c o ns id e re d equivalem to ,at of th e finished pan fo r quality a ss ur an ce . S ev er alformative annexes a re provid ed . inc lud ing a c onv er ..
on table betw een ultim ate tensile trength, V ick ers.
r in ell a nd R oc kw ellhardm .valu .
The foU ow ing calculated examples repre emtual gear sets for w hich performance is k now n
om eith r baek -to-baek testing or field experience.
each case, a few geometrical value have been
anged to make the example generic.
IS O does not d ir ec lly c alc ula te an allowable
ower for a gear I ll. nor doe A G M A calculate a
fety factor.In order to make the comparison tables,
e ISO allow able pow er w as calculated from the
fety factor. T he calculation w as m adewith th e v al-e of K H~and K. obtained at nominal load. disre-arding the change ill tho e factors due to load
ependence. T he AG MA afety factors w ere eal-
ulated by comparing allow ablestre numbers (0
alculated tress numbers, asin WSO.
120000
I I M E
I
10 0 ~~~i~~~~ __ s s~ . _ _~~ ~~ ~ ~~~ 2004 5 0 '5 0 0 6 0 0 ' 1 0 0 I lO O
S u r fa n H a n in lS l H VI
nd allowab'rll1Itu numbtfll,bendi a l.
3W i n d u r b t n a ,L S
& 3 Q { 2 U G J Itil
lXI I402I1 . 1 54 2 1
1 . 2 3I J IlA O1 . 0 2
Carburilld
Con lnlnns ~ 311: IIC .= . .~r---+---+-- , ,,--II I DOlIC n re h lrd n , ~ 2 5 H R C - ._ ._ ._ ._ . .-~ M OJomlfvhtrdlnlbilr\V11 J
l12m m - i. ~ ~ . B . + _ -._-.-t-.-_-;//.,.....~
C ore hardn ess ~2 5 HR C a o o o }-_JDminv hardanabll ityn J ~1 2 m m
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G E A R E N G IN E E R S , IN C .C D m p a r i s o n ,ISO Y. ,AGMAr 8 1 in g s f orlour e~ .mpIB glill se b: 1 4-0 ~t -l 99 8
IN P U T D A TA :C e n t e r d.stancB 39.324 1 .5482 2M.7 10 .5 630 .001 24.8032 2378.03 93.6232Pinion No . Teeth 1 3 1 3 17 17 25 25 2 4 24Goa NQ.Teeth '68 68, 69 69 151 151 21 0 21 0Module/Dia. P ilch 0.9071 28.00 8 4.23 7 3.83 17.602 I.....Pinion face width 1 6 .00 0 .6299 1 20 .6 5 4.75 2.04.00 8.0315 91 U O 36 1G e ar fa c e w id th 12.70 O.S 120.65 4.75 I 204.00 8.0315 91H,0, 38, ID o u ble h e lica l No No N o No No No Yes Y e s
.... -.. -~ifi~~~~O.hlJim ... ------ .'----.. -_.. .. --- 0:&97 ' - - . - -b :i ts i - -- . . - - . 'O~S~8j'- -- . .. -'r~'a 'r' -, --. - o: ~ .. _ . if ~5 .- -- .--.Ji.~}~ ---..--.~~2X gear, 0.5987 0.5987 0 .4614 0 .4614 0.2159 0 .21S9 -0.462
-0.402.N or m al R e /.p re ss u re I ng le 20 20 20 2,0 2.5 25 17.495 17.495FIef.h e lix a n g le 11 17 9 9 '2 12 30 30P in io n t ip d i. 14,94 0,5M 121.03 4.765 96.41 7.1321 536 .44 21.m1G ear tip d ia ., , 67.1M 2.651 436.35 17.179 1091.59 42.976 4283 .46 158.64Pinion ccnstr:Solid II), Aim (2 ) 1 1 1 1
'-- ' . .--~~ f~~~~r,~oen.----.----..--------..-0---' ---- ... ---'Ii'---...- -... __ . . ---. ----. . 0- . .- .---. .. - .- . .. ~.. . ---- .. .1 1 ._ . - . - -- ... - - ..Q.- P in io n n o . o f w eb s 0 0 0 0G e a r c en s tr : S o lid(I), R im (2) 1 I 2 2Geer we b thickness 65 50Gear rim 10 1011.6 4064Gear n o .o f w e bs 0 0 1 2Accura cy grade, pinion 6 '1 1 6 1 1 6 1 1 8A cc ur ac y g ra d e, y a .r I 7 10 6 , 11 7 10 8 9
....---.--~~~:~~1;~~~~~~i~~m V .~I 1 - ,- ' }:g - -.- --.. -.--g ~;:-- ---.------'U - - - - - .- - - - . - . . -1 l{ { --- -- -- --A oo t f ille t r ou gh n es s , p in io n , m u -m 2.28 3 2 ' 6 . 2A oo t f ille t r ou gh n es s, g ea r,m u - m 2 .28 3 2 6 .175C r o w n i n g c o n f ig u r a ti o n 2 2 2 0B e a ri ng . rr a ngamant 3 5 3 1L oc a tio n o f c o nt ac t 7 7 7 7
I n it ia l m i s a li g n m e n t 0 0 0 0In pu t fe ce lo addistr, fe ctor 0 0 0 0. '--._~ r i ~ * ~ ~ ~ ~~ : ~ ~ ~ ~ ~ ~ ~ D _.-- -- . _ . --. .- -- -~-- -'- l' - -- --.. .. 1 : - - - - - . . g ~ 8~ t _ .~i: - ~~ 8U - ---. .g ---- ..---8 -Des ign tip r,elief 0 0 0 .035 0P in io n to o l a d de n du m f ac to r 1.25 1.25 1 .40 1 .4lI 1.30 1 .30 1 .15 1.'15G e a fto o l a d de n du m f ac to r 1'.25 1.25 1 . 4 0 1.4 l1 ' 1 .30 1 .30 1 . 1 5 11.15P in io n t oo lprotubaran ce 0 0 0.2977 0.0496 0.294 0,042 0 0G e e r t o ol p r ot ub e ra n c e 0 0 0.2977 0.0496 .0 .294 0 .042 0 0Pinion 1001ti pradius 0.30 0.30 0 .40 0.40 ' 0 .25 0,25 0.20 0 .20G e a r t o olti pradius. 0.30 0.30 I 0 .40 0 .40 0 .25 0.25 0.20 0 .20
--- ---- . ~jg i~~~el~r~i~\~~t~~g ~IL . --- . - - .--- . --- - -- -- ---- -- . - - -- . - _. -- .- - --- -- .-- - .- - --- -- -- - -- .- -- .. - --- - .~~
I H a rdn ess sca le, p in io n H R C H B I H AC H R C H AC H AC H B H BH e r dn e ss s c al e,g e a r H R C H B H R C H R C H R C H R C H B H BPinion surface hardness 56 578 58 58 58 58 284 2 84G e a r surface hardness 54 548, 58 58 58 58 266 266Pin io n m a te rie l IF ln d (B ) Eh C a rb. Eh C a rb. V THPin io n m a te ria l subc las s 1 2 1 1G e a r m a t e r i a l IF In d (B ) ,Eh C a rbo I Eh C a rbo V T H
. .---.---~~1~~~W~~I~n~~~~~~--- -- ..---.~li _. ---2' _. . ,dti-------- 2 - -- . . 1 . -. - -~11'.. - .. T-' -- . - ,;}X-.- -- '2 -..G e a r m e te rila l g ra de I0 Il0 : 2 : M O . 2 M O 2 . M X 2Bear ing span Z20.7B 8;692. 288.54 11 .36 64\).00 25.197 1317.60 51.814Pinion oNset 39.B5 isss 51 .82 2.04 60 .00 2.36 2 0 .00 0P iOiOns,h' ,a f t 'QU,tsid,diamet,er 20 .64 0 .8125 8B._.90 3 .5, 150 .00 , 5.900 3 :30 .0012.992 IPin io n s h a ft in s ide d ia m ete r _0 0 0 '0 I 0 0 0 0P in io n Id le r? No No No No No No No No
._ .~ ~ ~ ~ ~ g ~ ::c ~ o ~ -.----- . - -.-..- ~:~~53 _~r -b~\r-----~~ .k~ .1~ I~ .- - - J ;g j - - - P in io n s p e ed , 1750 1750 340.4a 3M),48 180 180 115 175 '11I n p ut p o w er ,KW 0.373 0.373 224 224 300.628 300.638 1475 1475lol lm i m u m s a fe ty f a ct o r, d u ra b ili ty 1 1 I 1 IM i n i m u mnfety f a ct o r, b e nd in g 1.50 tOO 1.20 1 ..20Pittin~ l ife required, hours 10000 10000 10000 10000 100000 100000 lOOOO1J 10000IJ B e n d m g li fe r eq ui re d , h o u rs 10000 10000 I 10000 10000 : 100000 100000 100000 106000Pitting permitted, p in io n ? No i No : No No
- - - - . .. - . . r n 1 ~ p f& ; ~ i~ ~ d t a ~ ~ ~ i .l p in io i i- - . .. - -- -- . - . . - . .. .~9. - . . -. -- - . . -- - . .. - -- . ~J l .. -- --- .. -. . . .. ,- -- -.~ ~---- - . -- --.. . --- ~ P - --- .. ----. ----I n p u t p i tt in ghIe f a ct o r, g e er 0 ' 0 0 0I np ut b en d in g lif e la c to r, p in io n 0 0 0 0I n p ut b en d ln ~ lif e f actnr, gear 0 0 0 0I n p u t p i tt in gl te Iaetcr fo r ]0 10, pinion 1.00 1 .00 0.85 0 .85I n p ut P it tin g I 'f efactor Io r 10 10, gear 1.00 1 :00 0,85 0 .85Inpu t bendng lif e f ac to r f or1 0 1 0 ,pinion 1.00 tOO' D.S5 0.85I np u t b e~ dn .g lif e f ac to r f or10 10 , gear 1.00 1 .00 0.85 0.85K J ~ m a l ll :oi l V I S C O S i t ya t 40 C 320 220 320 560
E xa m p le N um b er
S landard
1
ISO G e er M o to rAGMA
2
IS g at alo g r ed uc :G M A
3Wi n d T ur bi n
I S O . IU,MA
4
I SO R o llin gMiliA G M A
I~A LC UL A TE D R ES UL T S , S I U NIT S;Pi t t ing s a fe ty f a ct o r, p in io nP in in p s a fe ty f ac to r, g ea rB e nd in g s a fe ty f ac to r, p in Io nB e nd in g s a fa ty f ac tu r, g ea rA llo w a bl e p o w er ,K WP in i on a ll ow a ble p o w er ,)liningG e a r a llo w ab le p o we r, p in in gP in io n a llo w ab le p o we r, b an d in gG e a r a llo w ab le p o we r, b en d in g
Face l o a d d is U t bu 1 io n f a c to rD y na m ic fa cto rP it ti n g s t ra s sat in p u t p o w erAllowable pl1 tmg s t re s s, p in io nA llo w ab le p it tin g s tr es s, p e arP in io n b e nd in g s tr es sat I n p ut p o w er
AJJowable b e n dm ~ s tr e ss , p i ni onG e ar b en din g s tre ss a t in p ut p ow erA llo wa ble b en d in g s tr es s , g e erU fe f a ct o r, p in io n P it tin gL ~ e f a c to r , g e a r p it tin gL if e f a ct o r, p in io n b e nd in gU f e t a c te r ,gea, bend ing
22 G~AR TECHNOLOGV
0.92 1.97 1.01 1.08 1.23 1.09 1.02 1.070,91 2.04 1.07 1.11 1.30 1 . 1 4 1.04 1.072.97 2.09 1.71 1.25 1.40 1 .02 2.15 1.322.41 2.20 1.75 1.27 1.42 1.07 2.01 1.230.31 0.78 2 5 6 . 11 259,83 421.4a 30544 1538 1 6 8 00.32 1 . 4 5 2 5 6 . 11 259.83 456.30 359.11 1538 16860.31 1 .56 256.11 277.12 509.63 3 9 0 , 0 8 1605 168G1.11 0.78 383.19 279.13 421.4a 305.44 3 1 1 6 19440.90 0.82 391,24 284.12 425.69 321.80 2968 1810..-- -- ---- -_..- - -_.._._-- -....- - -.. .- .....- -- .....- -- - - . -- -. -. . . . . . . . . . . . . . ..' ..... , _ . 0 . _ . _ _ . . . . . . . . . ._ _. _. . . . . . . . .-- _.._.. .-- _. . . . . . . .-
2.083 1 .16 1.266 1.2209 1.084 1 . 2 7 3 1.684 1.841 .036 1.068 1.005 1.049 1.005 1.081 1.025 1 . 1 8 51149 61 4 1 4 1 9 1344 1 1 7 3 1275 73 8 7561062 1209 1518 1 4 . 4 8 1445 1393 5 B O I l1043 1255 1518 1496 1527 1452 769 B 0 6244 68 512. 374 61 B 44 5 243 2234a2 14 2 4IlS 122 452 43 6 2 9 430 2 67 503 376 6 36 43 6 26 4 2 3 9485 14 6 8 7 7 4 7 7 751 467 4 4 3 2931 0 . 8 9 9 1 0.933 0.91 0.898 0.911 0.8991 0.933 1 0.9ti4 0.962 0.936 0.974 0.9441 0.937 1 0 . 9 6 4 0.889 0 . 9 3 6 0.889 0.9371 0.965 1 0.989 0.921 0.967 0.929 0.974
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rdened materials, which al 0 affects the rated
pacity of this gear setExanlple 2: Standard catalog .speed reducer;
his is the low peed me h of a carburized and
ound double reduction catalog reducer similar to
hat manufactured by several large companies in the
ternational market. Gears ofthis type rate almost
entically under AGMA and [SO standards. MallY
ll cale laboratory te ts have confirmed the e rat-gs. Since this is a catalog rating, the application
ctor is et to 1.0..
Example 3: Wind turbine speed increaser. Theind turbine example is a carburized and ground
eed increasing drive subject to extremely variable
ading with high overloads from wind gu ts and the
ature of the driven generator. An application factor
as chosen for thi drive based on a Miner's rule
nalysis of the effects of the load spectrum and
pplied to comparethe [S O and AGMA ratings of this
ear mesh. The ISO method calculates about a 14%gher pitting stress safety factor (30.% higher power
atin g) th anAOMA. primarily due to the difference in
H Ii. The AGMA rated capacity of this drive has been
onfirmed by te ting and field e xp erie nc e. Itshould beoted that the calculation of capacity by Miner's rule
more complicated under the ISO standard, since the
alue ofload distribution and dynamic factors are
ad dependent, requiring a recalculation of all factors
r each tep of the load spectrum.
Exampl.e 4: Large through hardened roUiing
in drive. The mill drive example i from a dou-e helical (herringbone) rolling mill stand which
urvived 1 5 years at 8 5% of the rated power, fol-
owed by ten years al fu II rated power. It was
placed due to wear and pitting of the roots pro-
les. The [SO pitting safety factor is slightly lower
an the AGMA value due to differences in the
lowable stres number. W itthis example the IS O
oad distribution factor i. s lower than AGMA,
which partially offsets lite difference ill allowable
tress numbers.
Figure 5 compares tile minimum calculated pit-ng and bending stress safety factor. for the four
xamples. The examples are characterized by center
stance in the figure, but it hould notbe irnplied
at center distance alone explains the difference
etween the ISO and AGMA afety factors for these
our very different gear sets.
What Causes the Differences in Calculated
Capacity tin These Examples?
The tabulated results show that the calculated
itting capacities are very similar. with difference
eing mostly dependent on the evaluation ofKH~e face load dislribu.tion factor. The difference in
he dynamic factor also has all,effect. particularly inery large gears.
E x .1 E x .3x . 2
1 0 10 0
G e nt er D i s a n c a, m m1000
(log8r1thmlCSClle)
F ig . 5 - Pittin gl B nd, be n d in g s Ue S Ss a fe ty fa c to rs fo r fo urellampl'lls.
In comparing ISO. to A G M A . remember that thecalculated IS O bending stre numbers include a
sire s concentration factor Ys. which ranges fromapproximately 1 .4 '1 0 2. 2 depending on tooth form
and fillet roughness. It has a value of Y ST = 2.0 forthe test gears used to develop, the allowable stress
numbers for the materials. In short. both the IS O c al-
cu late d ro ot [res numbers and the ]So. allowable
stress numbers are about twice the AGMA numbers.
T he calculated b e nd in g c a pa e it ie according to [S O
ar e generally much h ighe rthan the capaci tiesaccording
[0 AGMA It appears from these examples that a m i n -imum ISO bending safety factor of 1 .3 would be
required to have the same conservatism as the A G M A
rolling practice. It shouldal 0 be clear from the exam-
ples thai there isnot a simple relationship between the
ISO and AGMA rating results. In order 1 .0 understand
how your gearswill rate under ISO 6336 yo u will have
1.0 go through the calculations case by case and com-
p ar e th e r es ults .
You Can Have 8 1 Velce in Future R,evi ionsof the ISO 'Gear Standard .
If you find errors or disagree with the ISO stan-dard's calculation of the capacity of a specific class
of gears, you can work through the ANSI Technical
Advisory Group (TAG) to IS.o TechnicalCommittee (TC) 60, sponsored by AGMA, to sug-
gest changes to the standard. Those suggestions
should be well supported by calculations and test
results to demon nate the need for the changes pro-
posed. The ANSI TAcG meets regularly to establish
the U.S. position on [SO standards. If there is a
U.S. consensus for your proposal, it will become a
U.S. proposal to [SO TC60, which is responsiblefor changes and updates to the standard. TC60 is
already working 0.11 the next revision of [SO 6336,
which is due to be completed in 200 1 . 0
Tel W t V W Ik
If you found thil artic'- ofinterast and/or ultful.plaase circle 2It
F o r m o ra in fo n n 8tlO n a bo utG ea r ~ 1I I c . .Circle203.
JANUARV/FEBRUARY 19&9 23