Download the March/April 1999 Issue in PDF format

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Inthe past, you knew us as Pfauter-Maag CuttingTools. But with the addition of Gleason" bevelgear cutters and Hurth" shaving cutters, we'renow able to meet. .any and all of your gear cuttingneeds in ways not even Pfauter-Maag Cutting Toolscould have achieved alone.

In recent months for example, new tough, healresistant HSS and carbide materials, combined with.advanced new POWER' LUBE COATINGS"'.have resulted in POWER CUTTiNG'". This newGleason Pfauter Hurth technology givesmanufacturers the ability to produce bothcylindrical and bevel gears at speeds many times

B"vel or cylin,drical'... fD.ughingDf finishing., .. wei or dry... HSS Df carbide ... thepossibilities'are' now as' b'road and ,diverse' as our fa'st..gro'wing pro',duct line.

Just imaginewhat we can do ,tD,gethel"".

Gl,eason P'F',IlUTER HURTHthat of conventional HSS tools. Even better, gearscan be cut without the use of coolant, completelyeliminating the disposal costs and safety and healthissues associated with wet operations.

It's just one example of how our tooling ..experience,and resources will help meet your gear makingchallenges going into the next millennium,

CUTTING, TOO"LSCORPO'IRATIIIOIN

Formerly Pfauter-Maag Cutting Tools

1351 Windsor RoadLoves P.ark, IL61111 USAWeb Site: http://WIWJ.pmcl.com

Phone:B15877 8900Fax: 81S.877-0264

E-Mail: [email protected] 1115

http://WIWJ.pmcl.commailto:[email protected]

THLATfSTINNOVATION,IN HOBB/NG.SUPERIORQUAUr( SERVICEAND DELIVERY.

The Iouma! of Gear Mallil/acturing

FEATURESA New Approach to H:eat Treating! P,arts Washing .A combination of approache for less expensive clean parts 13

Fatigue Aspects of Case' Hardened Gears,Case depth and its effect on contact fatigue and bending fatigue 1'.

DIRECTORY

Gear IFundamentals:Metallurglica'l Aspects To IReConsidered in Gear and :Shaft DesiignAn overview of the factors affecting and.the methods for improving gear metallurgy 49

1999 HEAT 'BlEATING DIRECTORYFind gear heat treating erviees and products l6

DEPARTMENTSPublisher's P.ageNavigating Uncharted Waters in Cyberspace 7

RevolutionsThe Wm-Id's Most Slippery Solid, Vector Gears, _New Heat Treating Technology and Levitation. for Metallurgy 9

Technical CalendarImportant indu try event you should know aboUl 1J

6410..& AThe column that answers your gear que tions 2-

Illndustry Re,pon . _A new report on the state of the gear industry 391

1

Adv,ertiser IndexTry Rapid Reader Response for neady instant i.nfonn.atiolll 48:

Industry NewsStay on top of industry everus 56

New ProductsNew tool for gear manufacturers .." 58

Webtind'ersVi it the e important Web sites .160

Cover an CDUrIISjI' 01MitsubjllUIMllllllinlCarpolllliDN. YIri, NY.

CI!assifiedsServices, Help Wanted and more .162

Add ndumTake a lour of the Gear Industry Gallery of Fame ..164

Precisionold~ng

cGearingand no_ ady e,quals

UA mechanicallE UGEworkholdingsollutiio,n will immedi'afely Iboostyour part quality and productiivity.

:;Clamp on a symmet,ricalor i~reguliar surface-pitch diameter ,cl'amp~

ingl is our absolute specialty.

IBut let's get preelseII ~''''Aocu~aie,''to''~Hhi'n''20'm'ii'iio'nih''''''

of an inch

~ ~~~~~"~~.~:~~~~~!~!~, , , .~: ~~.~~~~,t~.p'.~.~~~.i.!~:~, " ..~.,.,.!~~T~.~~~~:!'!Y.!:.~~~~~~~~~.g.~~bil.!~,~..,..~~~y...~~..!~.~~~!.~..~.~.~..~~!.~.~~~.~,~",..~.~,~~.~.!~~!..~~!I.!~~~.~!.~,.

I

~et"sdiscuss an EMU precisionlworkholdingsolution for you todayl

u508 393 1310 Fax

CIRCLE 103

ED:ITORIAlPo,blis,her & EdUor-in-'Chier

Michael Goldstein

Managing Editor William R. Stott

Associate EdItor Charles M. Cooper

Tecbnil:al EditorsRobert Errichello

Don McVi[lieRoben E, SmithDan Thurman

ARTArt Dim:tor Jean Bartz

ADVERTIS,INGAdvertising Manager Patricia Flam

Adver,fising Coordinator Donna Lawson

CIRCULATIONCirculation Coordinator Brian Sessfer

INTERNETInternet Editor Daniel Gcnsiorowski

Gear Industry lIome Pagenl SalesPatricia Flam

powertransmission.com SalesAnthony Romano

RAN.DALl PUBLISHING STAffPresident Michael Goldstein

Vice .Presidcnl. Richard GoldsteinControlJer Pallid Nash

Accounting Laura MlIDionArt Conmllant Marsha Goldstein

Phone: ,847-437~E-mail: [email protected]

Web: www.geartechnolop.comwww.powertronsmlsion.com

I I

BPAW

VOL 16, NO.2GEAII TECHNOI~OG\'. Tb. J""rnal Qr CoarlI1anofXlUril)g !ISS..., 0741-6l1.S I .. pul>1"hod bll""nth-Iy b, ~I I'UbhoIlm~. tee., 14ZS Lunl Ay.n .... p.o.110,1421>. E1lI Grove Yul-se,1L ClOO07, (l!4714~7-66!);1.c...... Jlric

II processes de!;cribed in OEAR TECHNOLOGY con1"",,to wUfid cogifiCCrillg pruC1u.."'C. Nen.her the ..lHuhan 1'k"1f' ~

I pubhsber call be held respen .. blc for Injun es susuunedwhile fllo",ing !he proced .... , described. PO

PUBUSHER"S PAGE

I'd like 'to~ "IIIII"ith you,a vlslon. 0: "t'he~ It lakes place in cyberspace. and irs coming soonto a computer near you. Whether you like it are already possible. Some will become practIcal ve~on. Onceupon a time, e en the fax machine seemed like an expensive to). -'-01.'. hardly a business Slln i\~~ withoutit, The arne will boW true (ormoen of dii~emerging Internet tecfmology. O~ course, some uf tnese ideas v.illprobably go the V..lY of the lelex machine .ma C);JM! onlylong enough to be replaced by something better.

E-mail and the Web have become the~'something better" of tooay. By oow, most of you hav personal or business e-mail accounts.You've surfed the Web, and you've become familiar", i.th the Internet. But the best of today'v loo[, continue to evolve, and the pace ofchange. both in hardware and software, is 1: sier than ever. U!aming how yoof"Company can-best use the Internet is an inc ntal prdeas.Continually building on your knowledge and fami! arizing yourself with the latest t chnologies w i inexpensive Lime well s 'nt whenyou consider the pos-ible long-term implications of II competitor who's using his Web site to showcase his products and sell tire! onlinewithout ever leaving his office. You don't want to be' communicating v. ith stone \>IIblehand chi,..:!> when your competition is ill onfer-encing and leading virtual tours.

Most companies use their Web sites today as electronic \ er-, ions of their ptll1ted mate rials . Having this informal! available 24 a dayfrom anywhere in the world certainly has its adV8ntage~, but this is only the beginning. In my vision, compan) Well sites look less like onlinebrochures and more like stan: [mnts and showrooms, a place to do business. At your Web site, you'll develop relationshrp- beit remotely.with far-flung customers, and you'Il do more and more of your company's business.

We're investing convid-rable effort into this year's Show Central, our 3D version of AGMA'sat www.geanechnoLogy.colII b} May l.'You'lI have 10 download a small piece of software to fullyexplore Show CentraL. but we're confident that when you visit. you'll see how powerful-an electronicshowroom-or better yet, a whole shopping mall fuji of them -could be (Qr buyers of machine tools.Experiencing Show Central as potential buyers will also give you vome ide14~about how ,You mightbe able to implement these technologies fo youI'" customers on geanechnology.com, powertrans-mission.com or your own Web site.

Show Centrol is not yet quire as advanced as my vision of the future; butour first step io that direc-tion should show you enough that you and your company will be convinced to take the next step with us.

J!:fMichael Gol

http://www.geanechnoLogy.colII

We offer "Jore ... _Hydraulic Expansion Arbors

T.h~1advantallg~s are ObIV.ioU51: < .00012" TIR

Maintenance free totally enclosed system ensurestrouble free operation .

Workpiece clamping for:-Grinding-Sharpening -Turning-Milling -Inspection -Balancing-Pixturirrq

Standard hardness: 52-54 HRC.

Multiple workpiece clamping.

Typical Appl.ications --------------

Tooth ...Pratite Grinding

Turning

Gear Hobbing

Now ManufactUired in Germany and the USA!

REVOLUTiIIONS _

Vecto,r GearsWelcome to IRevolutions. the col-umn thaI brings y;ou the .Is.test,most up-to-.dale' Bnd eBsy-to-re8dinformation .8boUI the peopleBn.d techn,%gy of the gesTi.ndustty. Revolulions welcomesyoursubmiss;oRS. Please .sendthem to Gear Technology, P.O.Box 1426, .f/k Grove IViliage, I.t60009, .fax (847) 437-6618 or ,[email protected]. Ifyou~dlike more inionD8tion aboutBny of the snicles that appear,plesse circle the appropriate num-ber on the Re,der Service Card.

World's Sl~ipperliestSolidThe Guinness Book of World Records

lis Is a patented dry-fil.m lubricant fromGeneral Magllaplate Corp. as the materi-al with the lowest coefficient of friction(static and dynamic) of any solid.

Hl-T-LUBE was invented in the 19505for use in fighter aircratt, The lubricantwas further developed for NASA in the1960s to be applied to the mating surfacesof critical moving parts in space vehicles.Parts treated with ID- T-LUBE can operatein extreme temperatures (-360"F to+WOO"F). vacuum a:nd high radiation

I j environments, maintainjng a coefficient offriction of 0,03 while withstanding com-pression load in exees of l50,000 psi.

ID-T-LUBE i made up of five layerof metals and alloys that are electrode-posited and pennanenLly bonded to thesubstrate metal. It.can be applied to steel.stainles steel, copper, copper alloys Q[aluminum. Typical applications includegears, rollers, bearings, pistons enginesand other movingparts.

The 1998 edition of The IGuinne s Bookfeature an interview with HJ-T-LUBEinventor Dr. Charles P: Covino, who.describes how somelimes luck is betterthan design. "l put five materials togetherand composited them into a lubricant. Andit worked the first time." Covino said.

Clrde251Above: A pair of VtctoJ' gelll'S.Courlesy oj Flowd!JJ4 Corpora/ion.

Cireie 154

I

Gelll'S ami sprockets are protected .against wea.r,!flicking. and gaUing by Glllltral Magngplllte 1HiT-Lube!l synllrg-vtic .ooaling.

MARCHIAPFUL lUi 9

mailto:[email protected].

_-------------.IIIRiEVOLUTIONS -- -- -- -----------Unifo:rm MaigneUc He,8lting I piece. Induction heating systems place i :1

A new patented heat treatjng proce s the workpiece inside a heating coil,that produces a rapid and uniform Eddy currents are generated on the sur-through-heating of metal components of face of the component, creating a heat-varying hapes and mas may replace I ing pattern on the outside that radiatesinduction hea~ing.or furnace processing I or conducts inward toward the core. Coilfor some applications. i Uniform magnetic heating use two ---

Hath uniform magnetic heating and ! coil that are permanently fixed aroundinduction heating use c-oil to et up a i the ends of a C-shaped laminated core.linking 0'1 magnetic field, in the work-! Because flux energy pa es between

and it's Imade in AMERICA!

ANtI Systems Co. announces that lit ls now amanufacturing source of spiral gear roughingand finishing cutters and bodies.

We also can manufacture new spiralcutter bodies in diameters of 5" through 12"at present.

ANtI can also supply roughlngl and finishingcutters, hardware and replaoement parts formost 5"-12" diameter bodies.

Whether it's service' or manufacturing, con-sider us as an alternative source 'lor replace-ment parts. and hardware as well as bodiesand cuners.You'll be in for a pleasant surprise.

!NEW! Straight Bevel Cutters., R.oyal Oak, Michigan 48067Tel: (248) 544-3652 Fax: (248) 544-3922

II I ICIRCLEt1t

10 GEAR TE[;HNOlOGV

Bow IIn~fo,.m magnetic ,healing works. Counnyoj Mitsubishi lnlemaJ:ionol COlJWraJion..

the ends of me core in a linear fashion.the energy is evenly di tributedthroughout. the entire part. The re ultis a through-heating that doesn't relyon thermal conductivity to transmitheat from the surface to the center ofthe part.

Another benefit of uniform magnetichealing is that the same coils can run awide variety of parts. The system's PLCcan be programmed for a predeterminedfrequency level or voltage gain to auto-matically achieve the optimum poweroutput and beating rate regard Ie s ofpart size, shape or material.

Uniform magnetic heating ispasent-ed by the U.K.-based CoreFlux SystemsIruemational, Lrd., and is distributedworldwide by Mitsubi hi InternationalCorporation.

The CoreFlux proce ha been usedsucce sfuJly in lower temperature rangeapplications uell a the preheating oftransmission gears for laser welding;tempering transmission coupling anddrive shafts; shrink-fitting rotors, gearand bearings; and stress relieving orwheel hubs, gears and castings.Company officials expect ~o receivesimilar benefits in bigh-temperatureapplications such as through hardeningof gears and bearing ,

Clrele 252

_ _ REVOtU'TIONS, __

I !ew lechnlo:lo,gIY ~,elps FindAllo'ys of t.file,Futulre

The Marshall. Space Flight Center in

Huntsville, Alabama has a containerless

processing facility that will help materials

researchers determine how atoms arearranged in molten mixture which couldJead to the discovery of new, stronger and

lighter alloys and metallic-electronic crys-tals with, never-before-seen properties,

Called the Electrostatic Levitator or

ESL (pictured above), the new machinewas donated to Marshall's MicrogmvityResearch Program by Space SystemsLorai of Palo Alto, California. The ESLuses tatic electricity to levitate metal sam-ples, which are then melted with a laser.This allows measurements of various ther-

mal and physical propertie including 1I1f-face tension, viscosity, heat capacity,

undercooling nucleation-how far belowfreezing a molten sample wi.U stay liq-uid-and solidification rates without themetal touching the 'test container. Suchcontact could alter the test results, contam-inate the alloy mixture, or damage the testcontainer itself.

"The levitator provides important ther-

mophysical property measurements," saidDr, Jan Rogers of Marshall's Space

Sciences Laboratory, "By using hands-offmeasurements, we get an unhindered look

at the effects different proces ing tempera-ture have on experimental amples. Theinternal structure of material -l:ike met-als, alloys, oxides and semioonductors-are greatly influenced by heating and cool-ing rates, The levitator is helping us learnwhat structures and! what unique material

capabilities mayresul:t from manipulating

variou' metal-alloy sample ."Cin:le 253

rei. Us WUt: You nink ...If yc>ufound these Revolutions of interestand/or useful, please circle 200.

Proven reliability and unsurpassed accuracy are why we've remaineda Ileader in the Igear tool business for over so years .

.,/ Extel1lsive 'Stock- All Bore Sizes,/ F,RU CATALOG,,/ DiametIOI & Modulle IPitches,/ SOLID' ,CARBIDE: HOaS,/ Express Delivery,/ TRU-VOlUTE(!I (l'os5 AM,/ Latest (Doting Technology./ Quick 'Quotes

1llUSSELl,

I OlBROOKEIDERSOI, IIC.

Pho,ne: 201-6110-42'20Fax: 201-670-4266

2 North Street, w~

CUpper' Dli:amondloo,1 Co.47-16 A!uslell PlaceLong Island City, New York 11W1Phone: ,(718) 392-3671 I Fax: (718) 392-4124E-Mail: [email protected]

Polyc!rystallHne IDiaimOndDrlessing DiscsPrecision ProductsManufactured in the U.S.A,

Sharp IncludedAngles (200 Min), .

1 Sharp Radii(01.1m/m - .004" Miin).

1.1 Can be relappedmultiple times.

1.1 Better surface finish thanNatural Diamond.I. We also offer DressingDiscs in Natural Diamond. I

CIRCI.'E 133

"ARCH/APRIL Ieee 111

mailto:[email protected]

f'.xtreInely flexible and flISj tocontrol 9fnc:IIJ1J process,~ stock removal raes,No rEk ci burning due to thecold at . tv1"V"_

Invohle praiIe acauracyindqlendent upon filKiLliJonsoftl1 mochine tenpe ,_ ....l1igh precision worktool "few accwate Iea::Imodifications.~ JXBtioned leadrnocIificaions verthe entretocih in the ooubleflankgrindirYJ mode.Precise involt.te profilesin CIt'ai with modified leadin the double flank~mode.Generaed endreuefrmciIioib1s fer silMtly~ hgh speed gears.

for moreinform tioncall or write:

CIRCLE 112

HOIa' _ nenbau GmbH1nd1lSlrlcsh. 19'I).76275 EWiDgenJrr ..-........ -Tel. +49i243599-0fax +4972113599]65

_------------TECHNICALFOCUSII. _A New Approach to

Heat Treating Parts Washing

1m ew innovations in themanagement of heat

_ treating .paJ~s wash-_ ers are yielding powerfulcunexpeeted 'benefits.Simple. cost effective shopnoor practices are beingcombined in new ways todeliver big quality improve-ments and significant help tothe bottom line. Employingthese steps ,eady in 'theprocess can dramatically cutwastehauling expenses andgreatly reduce environmentalliabilities while continuouslyproducing cleaner pan .

Typical heat treatmentincludes heating to someaustenitizing temperature.then quenching in an oil bathto, harden the steel, Afterquenching. the parts arewashed and tempered toreduce residual stresses. Themanagement of the partswashing step-after quench-

Rick Terrien

ing and before tempering-isthe subject of this article.

How Paets WashingImpacts Manufa.cturiDgPoorly managed parts

washing operations canaffect manufacturing inmany ways. Qualijy is per-haps the single biggest issuefacing manufacturers usingheat treating. Tim Hoefft, aheat treating engineer withCaterpillar, describes theproblem: "Caterpillar contin-uuusly strives to increasequality throughout its opera-tions. An ongoingevaluationshowed that parts washingfluid used in heat treatingoperations could introducequality problems when notmanaged property. Partswashers covered with oil cancause poor quality washesand 'create other manufaclur-ing problems downstream ..Clean parts are particularly

fig. 1 - '~eat-.AII Melll'!s dllpl'oyedla grav.ity separata.r a'lIontbu, partswas'her conveyor line. !lily ,swface solution Is pumped up,from tha, WIshtank by direet suction skJmminll. Oil and gr,ila~a removed in tbe separator(cemer. top). 'Clean..,oil-fr,ee w!lsb lo'lution Iii ,continuously recycledl backto, the wash tank.

degreasing. However. envi-ronmental and afety con-cerns about olvenl haverecently led to a change toaqueou cleaners.

Eady formulation ofaqueous cleaners wereaggressive. high pH surfac-[ants designed to emulsify asmuch oil as possible. Oil thatwould normally rise to thesurface was changed into anoil/water hybrid thai washeld in solutlen, This slowedthe accumulation of oll onthe surface of the wa her. butit hid the problem in an everdirtier bath. Wben the capaci-ty of the bath. to hold emul i-fied oil wa u ed up, thebath lost its effecuvene s.Spent baths must be hauled

important in our gear manu-facturing operations."

Parts washers heavilycontaminated with oil. con-tribute to quality problems.]n poorly managed washers.clean parts are often sprayedwith oily wash solution orpulled through a layer of sur-face oil and grit prior to tem-pering. Gears and other partsthat are improperly cleanedcarry oil out of the partswasher. These oils becomebaked-on contaminants dur-ing the tempering step.Removing baked-on oilrestdues typically requiresshot blasting or other laborintensive reworking steps.

Oil dragged from theparts washers into the drawfurnaces also raises signifi-cant environmental issues.Oil heated inside the fur-nacesereates a smoky envi-ronment for the workers intile p.lant as wen as poten-tially prohibited levels ofhydrocarbon emissions outof me stacks.

Oily parts washers also Rick Terri'encreate significant long-termmaintenance problems forfurnace operators. Oil. burn-ing inside a tempering fur-nace degrades the fire bricklining. This leads to more fre-quent relining, an expeasivestep that keeps the furnace offline and unproductive.

In years past. quench oilwas removed by solvent

is a managing partner withUniversal SeparaJ()rs, UC ofMadison. WI. Univer olSeparators builds theSmartSkimTIIlU/!l' of suctkmskimmers aruigMllfry separa.torsforheot .,rearing partswashers. Rick has managedparts washers for over 20years and has de is/led andbuilt separation systems since1975. Universal Separatorscal! be reached a!www.srnartskim.eom,

MARCH/APR!L I g"g 13

http://www.srnartskim.eom,

_------------ITECHNICALfOCUS------------

WaslllTlnk

Fig. 2 - The SmBr1SkirnI direct suction skim bead (patent. pendinglnlmoves 'floating oilllnd olber 'contaminants Irom the wasil tank. A trans-fer pum,p sends-the sldmmad so:lution tal al gravity separator, 'Where oiland glita.rDrarnOVB d. .

the problem. Most employtooL borrowed from unrelat-ed areas of fluid treatment.The e typical treatments alsorely on old assumptionsabout cleaners. resulting inall oily wastewater streamthat is expensive and laborintensive to eliminate.

Typical methodscurrent-ly in use include:

Dr,Bg.Out Systems.These include oil belts, discs,drums and mops and havebeen the most commonmethod in recent years. Thesedevices have a componentthat rotates in and out of the

Fig. 3 - The all Ita:inless steelSmartSkim skim head (patentpending) from IUnivllrlldl :Sepllra-tors.away by licensed specialwaste haulers due to theirhigh pH and high FOG (fals.oil and grease ) count. Thecost for these hauling ser-vices vary by region of thecountry. However, all addsignificant cost to the man-ufacturing proces . Frequenthauling cycle. also result inthe need for expensivereplacement cleaners.

Current TreatmentMethod

Typical treatment meth-ods for keeping pans wash-ers clean have failed to takea comprehensive approach to14, (lEA" TECHNO-LOGY

To Gr,ayily Se,paralor

parts washer. Many use anoil-attracting (oleophilic)material to attract oils fromthe surface. A these compo-nents rotate out of the washer,materials clinging tothem arescraped off into a waste col-lection barrel. These devicestypically drag out a wastestream that is about 50% oiland 5,0% wash solution,which is expensive to haulaway and requires the contin-uous replacement of newwash solution and cleaners.

.. Cealescers. Thesedevices come in a widevari-ety of configurations, butmost employ tightly packed

beds of coalescing media.Oily wash water is pumpedthrough the media, causingoil molecules to coalesce andgrow larger. making themeasier to remove. Coalescerswere designed to work inpure oil-water elutions.Heat treating parts washersoften contain a much widervariety of contaminants, suchas grit. scale and soils. Whenoperators attempt to pumpthese solid through the tightpassageways of a coale cer,the coalescing media blindsover and becomes block:ed.In heat treating applications.coslescers must be frequent-ly taken off line and cleaned.

OffLine GravitySeparation. Thi methodrequire operators 10 pumpout. 'their washers into holdingtanks for further separationover time.. The large holdingtanks take up otherwise pro-ductive floor space and fre-quent labor input i requiredto manage the e fluid tran -fers. Emulsified oil is stillheld in suspension by emulsi-fying cleaners as there is flOmechani m for readily sepa-rating the layers of oil fromthe aqueous cleaner, Becauseof this, an oily waste streamis stillproduced,

Barrier Filtration. Bagand cartridge iil.ter havebeen tested to olve the prob-lem of oil and olids in thewash solution. These typical-ly Mind over quickly, and thecost of consumables be-comes prohibitive.

Membrane Fllrers.Membrane fllters are devicesthat filler fluids dOWIliID a verylight micron mting (typically Imicron and under). In wash-water applications, they aredesigned to remove emulsifiedoil. from the Cleaners. Mem-brane tillers quickly blind over

with contaminants, particular-ly free oil On the shop floor.membrane filters can becomeexpensive maintenance head-aches. Membrane filters alsodamag,e most cleaners byfillering out valuable cleanercomponent such as rustinhibitors and defoamers,Membrane filters cam beavoided, however, with a sim-ple change from emllls:iiyingcleaners to oil-splittingcleaners.

Em.erging Best Practices1'01' Heat Treating Parts

WashersAt Treat-AU Metals. a

commercial heat treatingfacility in Milwaukee, WI, alarge batch washerequippedwith a drag-out separationystem w not able to keep

lip with !.he large volume ofoiL It required frequent haul-ing afoily wastewater andreplacement of the washbath. according to mainte-nance director Ron Barnhart.

Treat-AU tried severalnew methods before settlingon a combination of oil-split-ting cleaners. direct surfaceskimming of the oily washsolution from the wash tank,and separation of the oilfrom the wash using an in-lime. open-channel gravityseparator (Fig. 1).

The emergence of oil-split-ling cleaners has been a greataddition to the tooibox of heattreating managers. Oil split-ter emulsify very little oil.Oil in these cleaners rapidlyseparate and rise to the sur-face. where they can be easilyremoved via direct surfaceuction (Figs. 2-3) ..Newer

versions of 'Oil. splitting clean-er are moving toward pHneutral formulations, whichcontribute to improvements :inworker safety.

Gravity separators exploitthe difference in specific

_-----1 TECHINICAL.lfOCUS1 _gravity between the oil andthe wash solution. Oil sepa-rates from a fluid ata ratedetermined by Stokes Law.This formula predicts howfast an objecI wiD ri e or fallthrough a heavier fluid basedonthe density and ize of theobject and 'the distance itmu t travel. Open-channelgravity separators exploitboth vari abies of StokesLaw. O~Imust rise onl.yavery short distance before itis captured on the bottomside of clesely spacedincl ined plates inside theseparator (Fig. 4).

Once separated from theflow. captured oil. with verylow water content can beremoved from the gravityseparator. This oil. whichcontains less than 5% water,is referred to as "dry" oil.

While oily wastewater pro-duced by other arrangementsmust be hauled away at theproducer's expense, dry oilcan rypically be sold for aprofit. Gravity separators dis-charge dry oil to a collectionbarrel without any movi.ngparts. The clean wash wateris returned to the wash tank.

Gravity separators alsoremove solids from heattreating parts washers.Difficult to remove, light-weight solids can easily con-taminate the wash bath.causing significant qualityproblems. Those solids aretypically made up of smallparticles of scale, grit, andstop-off paint, as well as a.variety of other contami-nant . Solid can be prayedback onto the pari: from dirtywa h solutions. Parts call

SIDEYIEWIDlscharge

Cleaned wash solution backto parts washer

fig. 48- Side view sbowiDg now 'of oily washer fluids through a gravitysparator. Oily solution is continuously pumped fmm the 'washer surface:BCrOSS Iml!'ltipfe separation p'lates. Oil and :.DHds slIplIlilte from '!he flow!by 'gravity while, daaned wash solutton is. returned to, Ihe washer.

- rI

1

--~LSolids- '-

ENDV1EW

Fig. 4b - End view. Inclinedl plales inside a ,gravitys8,lIar,ator capturean-d Iremon ,a/land solids sJlm!itaJlllo!lsly. Open clulDnel separation path-w~ys iuure DD cloggIng. Because there are Ino moving Iparts. &epBratormanagement is ,greiUy :slmplified.

OL,.... G.ear Hobbers,Shapers, Grinders andInspection Machines

RellMUlufaclureFetrofll/Rbu Idof Your Barber-Colman Machines

PamlServlce/Repalr of Yourl8arber-Colman, Bourn & Koch Machinery

2500 Klshwal.lk.ee 51.ROCk/a

FlsslerFocusingonDirect Honing!

Fassler K-300 & K-400Gear Honing Machines

Fassler ICorpoll:B1iion1311W. La,yton Avenue:Suite308Milwaukee. WI5J207Phon.e: '1414)1 76s.00nFalX:141'411 769"86101E-M'ai'l;fass'[email protected]

Fast, economical hardgear finishing processthat increases gear lifewhile reducing or elimi-nating gear noise. Internal or external gears- Spur. helical. or cluster

gearsWith Direct Honing

you can hob, heat treat,and hone your gears,tomarket requirements.

With UniversalHoning it is possible tofinish a family of gearshavin9 th e sa me toothcharacteristics with vary-ing numbers of teeth.

With Combi-Honingyou can rough and finishon the same machinewith honing stonesmounted in tandem,

MACHINE 'FEATURES: 5 and 6 CNC cnrnrolladaxes Synchronous drives an the K400 eNG control of lead crowningl and taper.' S hart setup times

1

I

1

CH_~RA.CTERIS:nCS OF HONED IGEARS: Increased wear resistance' High surfa ell fin ish Favorable machining marks for noise reduction'. Low surface roughness 'guarantees ,8 permanent oil film

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CIRCLE 125'16 GEAR TECHNOLOGY

____ TECH,NICAL, FOCUS 1 1also be recontaminated when ithey are dragged through grit j The combination in placeheld in the oil-at the surface of I at Treat-AU Met.ab andthese washers, j Caterpillar offers significant

Removing these types of ! benefits:solids has been difficult and, !,expensive. Coale cer have i

ebeen tried but their fllters are 'quickly blinded over by grit. i~-:o::'~U:m=;!used, bul these require ex.pen- i

~1;~J

Gravity separators do not l;require any consumablesand jare not blinded over by solids. jTreat-All Metals found that l requirementsthey don't notice any loss o,f I AU of this combines intoseparation efficiency until their j a rapid payback, as oppo edgra.vity separators become half ! to many other systems cur-filled up (50% ofllle separator I renUy in use. CaterpiUar'svolume) with solids, which l review of payback issues bas

!typical!ly takes months, i indicated that their system

Treat-AU is not the only ! will pay for itself in "wellcompany which has tried this ! under one year," says Haem.combination of cleaners and I However, the switch toequipment. Tim Hoefft of i oil-spUtting cleaners, suctionCaterpillar faced problems ; skimming and gravity sepa-similar to Treat-AU's wifh his jcompany's old drag-out. sys- !

3tem, "A review of existing 'oil ! oil-splieting cleaners are not:removal methods howed the ! good at removing alreadyneed for an upgrade," Hoeffr ! baked-on contaminants ..says. "Belt. and drum skim- !,l Also, gravity separators :mustmers were not able to remove be sized appropriately for thethe continuous input of oil ! job to be most effective.from the w hers." ! Small units can be over-

:tf~fl~~~I ff:ti~;7:{~fs~:all oil was removed from the tions, this new combination

can yield powerful, unex-

Cleaner parts. Extended bath life Cuts in waste hauling

costs Decreased cleaner

COSIS

Profit. from a fannersive replacement con umablesto stay on line.

waste stream Worker safety and

environmentalimprovements

Decreased maintenance

rators can require adjust-ments. POI' example, most

surface of the washer on acontinuous basis," Hoefftsays. Following successfultesting, Caterpillar deployedseveral of '!the systems ..

''Due Lo,ibe system's effi-

pee ted benefits to heat treatparis washing operations. 0

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_ -TIECHNIICALCAliEND.A.R------------_Marnh ]6-18. 4th World Con:gNS onGearing and Power Transmission.CNIT Pans La Defense. France. Learnabout the current trends in design. materi-al, heat treatment, manufacturing andapplication of mechanical 'Iran mis ion.Nearly 200 presentation on cylindricalgears, worm gears, bevel gears, plasticgears, sintered gears, bearings, cilains,belts and oth r power transmission com-ponents and y terns. Contact Mary eDeleris, eongres director at MCI, 19 Rued'Atltene, 75009' Paris, france [email protected] ..

April 11-15. Metalfonn '99'. RosemontConvention Center, Rosemont. IL. Discover!he latest innovative concepts and applica-tions in the metalforming indllSlry. There Iwill be over 500' exhibits atthi year' show. Ithe I"'_mest number ever at a Metalform

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April 13-15. 'Gleason Prauter Hurth iAdvanc d Gear .PI'OC - D namie ..Loves Park, IL. Th,is is a three-day, high-I.intensi.ly clinic on modem metal removaland measuring techniques fDr spur and Ihelical gears . t i tructured for manufae- Iluring and proce management withan !ill-depth look at modem methods, appli- 1cations and hardware in gear manufactlU-1ing and measlUingproce_se" . h includes ldemonstrations of modern gear cutting ;

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April. .9-24. Hannover Messe ..Hannover. Gennany. The Hanno er Faircontains the world' large l concentrationofelecmcal and mechanical power 'trans-mission. fluid poweruansmission andinternal combu tion engines. The showboast over 7500 exhibitors from 70countries, with 1.280 ill the power trans-mission sector alone. Contact HarmoverFairs USA at (609) 987'-0092 or log ontowww.hjUsa.com for more information.

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Aprill 20-22. Rapid Prolotypm,g andManufacturing '99. Ro emont COII-vemi on enter. Rosemont, IL. Thelargest event in the world focusing onrapid pr totypingand advanced productdevelopment technologies. Sponsored bythe Society of Manufacturing Engineers.Call SME at (3 [3) 271-1500 or visitwww.sme.orglrpa for more infonnation.

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Octob r 24-27. 'Gear - xpo 99.Nashville Convention Cemer, ashville,TN. Span ored by the American GearManufacturers A ociation, this is thegear industry' premiere trade show,boasting 5.3.000 square feet of space forover I.00 exhibitors represenung allfacets of the gear industry. For moreinformation contact AGMA at 1(703) 684-02H. by fax at (703) 684-0242 r by e-mail at gearexpo agnw.org.

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Fatigue Aspects ofCase Hardened Gears

Gi, P: ,CavaUaro & C. :Subramanian

The efficient and reliable transmission of me-chanical' power continues, a always, to be a centra!area of concern and study in mechanical engineer-i.ng. The transmission of power involves the inter-action of forces which aretransmitted by speciallydeveloped components. The e components must, inturn, withstand the complex and powerful stressesdeveloped by the forces involved. Gear teeth trans-mjtloads through a complex process of positivesliding, rolling and negative sliding of the contact-ing surface . This contact is responsible for boththe development of bending tres esat the mot ofthe gear teeth and the contact stresses at the con-tactiag flanks.

Gear Fatigueto analyzing the stresses developed io the gear

tooth, liti u efuJ to begin with a brief description ofthe dynamics of tooth coni act. Figure 1 depicts thecycle of contact and the contact pach of the teeth of aspur gear, The path of contact begins on the tip (theaddendum) of the driven gear tooth, goes through thepitch point. and finishes on the tip of the driving geartooth. The gear teeth are in contact along line C1-CS'At all poiats along this line, wilhlbe exception of thepitc'h point. the velocities of the contacting surfacesare different Because of this, sliding will. OCCUT (Ref.I). At ,the pitch point the velocities of the contactingsurface are equal and there 1S pure rolling. 111.eangular velocity of the driving gear tooth is thentransferred to the driven gear by a complex processof positive and negative sliding and rolling. The

ApprOBchl Recession

IF(g.~-M.shillg ,eyelllof gear teetll,18 tlJEAR TECHNO~OG)'

bending stresses at the root of the gear tooth and thecon.tact stre ses on the COlll'ac!ing flianks are there-fore generated by the loading conditions of the con-tacting surfaces. These stresses are re ponsible forthe dual nature of gear fatigue failures (Refs, 2, 3),

The bending stresses occurring at the root of thegear tooth arise due to. the transfer of torque fromone gear to another, The bending stresse , beingcycltic in nature, cam lead to fatigue crack initiation atthe root of 'the tooth. This region act as a stress con-centrater and the fatigue cracks which develop hereare classical fatigue fractures (Ref. 4),

The contact stresses ansing in, and on, Ihe con-tacting surfaces of the gear teeth ar a consequenceof the forces exerted by one surface on the other(Ref. 5), The e forces create pressure distributio.nsthat are dlirecdy responsible for the development ofshear stresses below thesnrface (Ref. 6). The magni-tude and location of these stressc are dependent onthe geometry of the gear tooth flank and the dynam-ic conditions under which the gear is operating (pres-sure distribution, involute radii, sliding velocitiesand coefficient of friction), The failures caused bythese hear tresse-s ace the typical pilting andspaUing types.

The overall design of the gear must take intoaccount these stress systems and minimize ,tlieif'effect on the integrity of the gear. While the materialof the body of the gem- tooth must display enhancedflexural ductility to counteract the bending stressesdeveloped there (Ref. 7), the flanks .of the gear toothrequjre a hard, wear-resisram surface with enhancedstrength to some depth below the surface to resist theorthogonal hear stresses developed in that location,

Tooth Root Stresses. In 1892, Lewi (R'ef. 8)made the fITS! documented attempt to calculate thestresses developed in the root of a gear tooth. Hisapproach was based on the analysis of a notchedbeam in bending mode, approximatingjhe gear toothshape by a parabola This basic approach is stillaccepted as 'fundamentally correct, with the excep-tion of the effects of what are now known as stressconcentrators, investigated by Dolan and Broghamer(Ref. 9). There are a number of ways of calculatingthe stresses developed in the root of a gear tooth,from the two dimensional analysis adopted by Aidaand Terauchi (Ref. 10) to th more sophisticated

finite element models which were first introduced byAndrews (R'ef. 11).

The bending fatigue of gears is principally gov-

erned by the geometry of the gear tooth. the loadingconditions and the material propertie at the root of

the tooth, The authors show. to some extent. the

importance of the geometry. but do not consider anyof the factors which .influence th material proper-

tie . The e metallurgical [actors depend 01'1 the mate-rial composition and heat 'tr,eatmenls adopted, as wellas 'their ubsequent transformation products and/orre idu I tre s distributions.

Contact Sire ses. From the literature (Ref. I.) itcan be seen that contact tre e developed duringthe contact of gear teellt can be approximated byrollers contacting under a known force. the liding

velocities of which reflect the dynamics of gear con-tact. From Figure 2 it can be een that the roller witha fixed sliding velocity will approximate !he contactof gear teeth at certain points along the contact path.Figure 3 displays the semi-elliptical pressure distrib-

ution generated on the surface efcontacting rollers.The problem of contact tee ,particularly the

problem posed by contacting rollers. have been di -ell sed by variou authors. The pioneering work ofSmith and Liu (Ref. 5). and more recently the work

on the ela tic hakedown of contacting surface byJohnson (Ref. 6) and the finite element modeling of

such contacts, by Hahn and associate (Refs. 12-14)deserve particular mearion, However. the stres 'statewhich exists on the contacting surface layers can besignificantly influenced by asperily interaction andcan include tensile and compre ive alternatingcycles and shear.

Two ,different types of plastic zones are producedby rolling and sliding contact. a hownin Figure 4.The first layer :is due to rna ro-contact width. usual-ly between ]-10 mm. The sec mi. which is much!>'Ilallower, is due to micro asperitie contact. Thi

depthh is of the order of O.5j.l~~O,j.lm and iobviously related lO surface roughness, Therefore.depending on the friction developed between the

contacting sliding urfaces, and the nature andstrength of the material of th roller. failure willeither initiate at the surface or: lib urfaee or, in somconditions, in both.

Metallu~ica1lPerspeeti es Relating toFatigue 1P,l!rformance in 'Carburized CearsWhile metallurgical factors such as oxidation,

decarburization. supercarbarization, carbide forma-tion. grain boundary segregation, type and densityall inclu ions pri': ent, microcracks and residualtre aU significrunly affect the fatigue perfor-

mance of cmrburized gears. derailed treatment ofthe e effects is well out ide the cope of this di -cussion, However orne of the e aspects. such a

fig. ,2-Cont.ct of iDvoM., spur our tilth.

Ifill. !-r,mSJI dis1riblltilHl in CDlI1IcUnll'nlUel'l. termiDalo J _do d in IHemiu tbIory.m:.idatioll and carbide formation. will be di cussedin relation to the case studies presented, The role ofretainedaustenlte will al 0 be discussed in view of11 highly controver Ialnature.

RetmnedAustenil't. The mechanisms responsiblef;or the retention o:fau tenite on quenching have beenreported in detail. in the available literature Utef .15-18). It i clear that of all 'the alloying elementwhich influence the retention of austenite on cool-mg. carbon has the greatest effect, Quenching tem-perature and cooling rates have all been reported toaffect the level of austenite retained (Refs. 15. 16).

The effect of the retain d au tenite on the fatiguere istance of ca.rburized eomponems has al o beenexten ively dealt wirh in theliieranrre. Nevenhele ~,some controversy still remains. [n the past, the pres-ence of retained austenite :has been regarded as detri-mental to the extent of adepting cryogenic treat-

ment I!O reduce the amount present.A more detailed picture h' emerged from the

inve ligations carried out by various authors. nOlabl,ythe work of Krauss (Ref. 19. 20) and Zaccone (Refs.

G. P. CavBllar,Q _ndC. Subr:amanianUI? professors and rt!ftQJ'CMFS!oclI.ving 011 ,cast hamtnlng andfuriBu/' in carburized gtul':!. alIht tan Wa,.k InstiruIt! oJ 1MUniversity oj South AIIltroUa.Th~' art' also lite GUllion of"Bf'TWilISFUlig'll' and CcmtaclFutillUt Ch{lrarl~ri lies of

Qrburiz~d Gear.

possible relationship between fatigueperformanceand retained austenite, which can account for someof the continuing controver y and explain some ofthe high fatigue limits being publi hed, The tran for-mation of austenite to martensite at the tip of anadvancing crack has been reported in the literature(Ref. 24) to bebeneficial 10 the fatigue resistance ofthe carburized eomponeru due to the associated vol-ume expansion of the tran forming austenite.

Ithas been poinsed out (Refs. 22, 23) that largeamounts of retained austenite are beneficial in termsof low cycle fatigue where the large plastic strainsinduce train hardening from the austenite to marten-site transformation and the development of favorableresidual tre e. However, in high cycle fatigue, therelatively low plastic strain do nol allow any trans-formation of austenite 10 occur. The same authorfound that the plastic strains needed. to transform theaustenite are directly related to the prior austenitegrain size and the morphology and size of the austen-ite packets. In fine grain tructures (ASTM 9.5-1 I),much lower levels of strain are necessary for trans-formation: (Refs. 23, 24), so that in high cyclefatigue, which is usually associated with very smaUamount of plastic strains, these structures will beable .to Ilr.il1sl'orm and resist crack propagation.

Work by many authors (Refs. 15, 25. 26). pointsto the reduction of retained austenite by cryogenicmeans as detriments] to 'the fatigue propertiesandfracture toughness of lite carburized componentbecause of the development of residual tensilemicrostresse in the remaining austenite regions.However to this author's knowledge, no systematicinvestigation has yet been published outlining thenature, or indeed the magnitude, of these

M'aCTocontact

E,quiv:a1ent SIrI in iru:ramem01 _

!f-tlI2w' .11,MicrIICOn111ct A.ctuallClln1 et

Figl 4-lIhrstnltion of two plastic lanes UDd" rolling contact d!!e to Imllcr,D lind mic"o contacl ..201 GE ....R TECHNOLOGY

microstresses, The effect of cryogenic treatments 011the bending and contact fatigue properties of carbur-ized gears C8fII be illustrated by result obtained fromgear research conducted al. the Univer ity of SouthAustralia (Ref:. 27-29). Figlllt'e 5 shows mal 'hecryogenicteeaunent was detrimental to the bendingfatigue properties of the gear. tested.

The effect of the cryogenic treatment on bendingfatigue propertie can be explained by only threescenario:

(a) If it is assumed that the retained austenite presentin these gears can transform on straining, and thatcryogenic treatment Q!ll:t reduced the Jevels ofretained au tenite, then tbe non-cryogenically !reatedgears have superior performance due to a higheramount of retained austenite, which can transform.ahead of the propagating cracking tip.

(b) If it is assumed that tile retained au tenite pre entdoe nru tran form on straining. then the non-cryo-geni.caIIy treated gears have superior performancedue to the cryogenic treatment imparting detrimentalresidual tensile microstresses in the remainingregion of untransformed austenite.

(c) If the retained austenite present does Wl.I. trans-form on straining, and its presence is detrimental tothe bending fatigue properties, then the cryogenictreatment ha a greater detrimental effect on thefatigue properties of these carburized gears than thepresence of retained austenite in the treated gears.

In all cases, these resuks point to a detrimentaleffect derived from the cryogenic treatment of thesegears. Figure 6 displays the experimental results ofcontact fatigue test carried out to determine theeffect of cryogenic treatment, This figure shows thattile adeption of cryogenic treatment has proven to bedetrimental to the contact fatigueperformance ofEn36A reel,

The role of cryogenic treatment on the contactfatiguebehavtor of the rollers tested is not as clear asit was in the bending fatigue section. This result fol-lows the trend found in the literature, where theadoption of cryogenic treatment was found to bedetrimental tothe contact fatigue performance ofcarburized components. ]11 particular. the experimen-tal results of Kiessling (Ref. 3 I), Razirn (Ref. 26)and Nakamura et al. (Ref. 32) have shown a directrelationship between high levels of retained austen-ite and high contact fatigue limits.

Case Depth and Core Slrength Requirements. Thedetermination of the appFOpriatecase depth. in carbur-ized gears mu t reflect the sire ses developed in and onthe gear teeth, as discu sed in the sections on gear

stresses. Th aforementi.oned duality of the tress sys-tem. in gears place certain limitations. or at least. COIl-ditions. which must be satisfied in the appropriateselection of the case depth. However, ilhas been di -cu sed 'mat the role of the hardened layer in the root of!he gearlooth i fundamentally different than thatrequired III. the contacting flank. The literature,asexpected, also displays thi duality of role.

It. has been known that a case depth elected onthe basis of contact fatigue will not necessarily per-form. al its optimum in bending.Thi has beenaclmow Jedged by orne authors. However in prac-tice.lhe case depth requirements for maxim.izillgbending fatigue resistanceare u ually overshadowedby the need for contact resistance, A great deal ofcontroversy still surrounds the optimum case depthfor bending/contact endurance.

The core trength i of ignificant importance inthe fnugue re i lance of the component This i part-Iy based on the core trengtb's influence on re idualstre se ,since the magnitude and indeed the polarityof lhe residual stre se d :veloped are dependem onthe difference in volume expansion of the 'case andoore. The larger th difference. the higher the re id-ual stres e . provid d that the core material doe .notyield (Rcf~.33. 34).

Thi simple criterion is, however, questioned bybert et al, (Refs. 35, 36) and McGuire et aiI' .. (Ref.37), who propo ed that a carburized structure is ba i-cally a two-component compo ite, and that each ofthese components will have signifi anti), differente.lastic .Iimitsand plastic pmperues. At stress levelsbelow the yield tre _ of both the case and COf'C. theoverall stre tate willI not differ ,from mat anticipat-ed in a homogeneou olid, However, as the load iincreased and th tre level. become higber thanthe yield tress of th core, the core will flow plasti-cally while the C3...e wiU still behave elastically,Becau e of the difference in the Pais on ratio 'forelastic behaviour (0.3) and plastic flow (0.5). thecase and core will have diffetent contracting tenden-cies. Thi create transverse stresses normal to theapplied stress in the case-core interface region Thisi .e entially a tensile biaxial state of stress.

The enhanced ductility of the carburized compo-nent, as compared to through hardened components.is derived by the development of compressive trans-verse stre se in the case, which help it resist theapplied stre e. In carburized steels, the presence ofretained austenite ill the case can provide a furtherameliorating effect if it can transform to martensiteon training. The volumetric expansion on transfor-mation, can reduce the biaxiality of the stres state inthe case. Thi model highligbts the impertance oflhecore tructure in the fatigue proces and it alsodefine the actual role of the hardened case. A deep

1~c--------r--------~-------r------~1500

1400 -

En36A Sh-lIow,cIU _01CryD' (1J~n3SA Shallow-CIII crr -,,mEn3&ADIlP-UII nD illY!! nd GBP (3)En3&A DBIP~CSI clYD GBP 141

IIJiICycles to IF"Uurl (LogiNI

101

Fig. 5-ThD Bllaet ,ofclYDgenlc Irutmlnt ,an tblllillding latign ,t g01l1'l'teltld.case is seen as increasing the degree of biaxiality atthe ca e-coreiruertaee while resiricting the ductilityof the case.

The effect of case depth 00 me fatigue properties ofearburized gears is illustrated bylhe results obtainedfrom tests carried out at the Uniersily of SouihAu tralia, They show that the shallow case deplh con-sistently our-performedihe tb.icker case depth, irrespec-tive 'of the post-heat treaIm nl process received (i.e,glass bead peening and/or cryogenic treatment).

The bending fatigue performance in relation tothe case depth initially points 10 tn.e various diffeI-cnces found between deep and thin cased g ars (Ref.30). Some of these differences were:

1. The hardne s of the shallow-case sample werelower than the deep-ca e aile .2. The retained au tenite levels were higher in thehallow-ease sample .

3. The microstructures developed in the c e of thedeep-case gears were different from those found inthe shallow-case gears.4. Tile crack initiation deplh was deeper in the shal-low-c-ase amples.

1he microstructural differences between the twotype of samples were mainly in the degree of n '11.-martensitic phases, which wereprimarly carbide net.-walks. These carbides acoount for me higl1er hardnessof the deep-case: gears (point 1 above), and the higheramount of retai.nedaustenitein thelhin~ase gears (point2 above)

26). has been suggested to be due to the adoption of I throughout. its depth. (k) (this can include through-a high carbon potential during carburizing, However,the reader is referred to' the work of Goldstein andMorell (Ref. 41), who have shown that. this supercar-burizing effect could also be due to Chromiumdepletion of the surface layers (due to, oxidation).

The deeper crack initiation of thin-cased gears isinterpreted as indicating the influence of re olvedstress (applied and residual) pre em in the interior efthe gear looth .. Fatigue cracks can only initiate inregions where the resolved stress is higher than thematerial fatigue limit. This location is also influ-enced by defects and inclusions, which will developlocalized regions of highly concentrated stress.

The initiation of cracks deep within the thin-casegears is the result of maximum resolved sire ses Ideveloped in deeper areas below the tooth's surfaceas compared to deep-case gears. This is alsoexplained by the bigher elution carbon eontent ofthin-case gears (Refs. ]5, 35,42), which will allowthe development of compressive residual stresses ofIII higher magnitude. The enhanced performanceob erved in thin-ca ed gears can be explained by twoseparate mechanisms. The first is based on the modelproposed by Ebert et aLCRefs. 35. 36) and McGuireet al!. (Ref. 37) regarding the rheological reactionbetween case and core. The second is derived fromthe microstructural considerations discussed above.

Case Depth .R.eq.uireme'ltsin Contact Con-,ditio.ns. Considering the stres distribution in con-tacting cylinders as outlined in the preceding sec-tions, it is dear that an element of material in or onthe gear flank willexperience stresses according toits position, the radius of the roller, the appliedlload,the respective relative sliding velocity and the coef-ficient of friction. Failure of the material, irrespec-tive of its nature, whether it is by exce sive plasticdeformation or fracture, is then .3 function of theparameters. outlined above and the true strength ofthe material. If the material's strength is a censtanr

~Ir-----------r----------'~---------.----------_1800 I

"00

En36A IDeep-case, GBP and Cryo' 111'ER36A 'Ileep_case no CI"'IOSlid GBP' '(211En36A Deep-case, Cryo, ,(3)~n36A,!eep~case (4)Enl6A. Thincase IGBP -.nd Cryo (51En36A Thin~case 'GBP'no 'CryD Ull

(5)

1200, L..:-----.l---- --_I........ --1 I11)4' U1,51 0& 10.7 10'

Cycles: to failure I(Log IN),

IFig. ,&-Ihe effect ,of ,cryogenic trea1ment on HIe coll1llct fatigue pel1onnanc:e of c&rburized roll'ers.22 GI;AR TECI'INOLOGV

hardened components uehas bearing races and/orausteaitized components), then it is rea enable toconclude that failure will occur in location belowthe surface where the shear stresses reach a maxi-mum. H. however, the coefficient. of friction igreater than about 0.3. signifying that these shearstre se .reach a maximum on the urface, failure willoccur on the urface (Ref. .5). However, in conditionswhere the materia! exhibits a strength gradient, as lthe case for case hardened components. the problemof prediethig failure locations become ignificantlymore complex.

The need to accurately predict failure locations incase hardened components is a basic prerequi ite inthe establishment of case depth requirements. It can,therefore, be stated that the main role of the hardenedlayer in contact situations is to ensure that the core ofthe component is not ubjected to hear stressesabove it cyclic shear trength, and to increase thesurface layer's resistance to asperity interactien, Inview of the shear stre ses developed. under 'IDecon-tacting urface, it is clear thatthe hardened layer hato be of such a deplit as to encompas not only thearea of maximum shear stress, but also the area fur-ther into the interior where, even though the contactstresses are not at their maximum amplitude, they arestill significant, The hardened layer should extend toa depth where the shear stresses decrease to a suffi-ciently low value 01 as not Ito pose a threat of crackinitiation in the core.

The role of case depth in the contact conditioncannot be ignored. Tests conducted at the Universityof South Australia show that rollers with. a. hallowcase depth display significaJiltly lower fatigue limitthan their deep-case counterparts.

The model. proposed earlier to account. for thmaterial strength in resisting contact damageexplains the difference ill the performance of rollerswith different case depths. this being due to the deepcase rollers having a higher contact fatigue resistantlayer extending deeper lntothe roller.

ConclusionsThe conclusloas to be drawn from the results of

the gear test pre ented are a follow :L Gears with. shallow case depths display higherfatigue limits 'than gears with deeper case depths.2 .. Cryogeaicallytreating the gears decreased both'the bending and contact fatigue performance of thegears tested.3. The contact fatigue performance of shallow ca erollers was significantly inferior 10 the deep caserollers.

RecommendationsThe bending fatigue treagth of a gear tooth lim-

its the amount. of' load applicable to the flank of the

Ijjjiiiii

thinner case depth, which would increase the allow- iiable bending stresses. does not impart the necessary i

resistance to contact that these stresses can generate. ![11 the past a compromise was necessary in terms of Ichoosing a case depth which would re ult in an :acceptable fatigue life.

The maximum case depth in the root regionshould be optimized for maximum bending fatigue,while in the flank ,ofthe gear 'tooth, the case depthshould be as deep as possible without running therisk of developing exten ive carbides or other non-martensitic phases. One way to achieve this is to usea two step carbllrizing process, where the componentis initially carburized to the case depth desired in theroot, taken out, and a copper coating applied to theroot region, The component is then recarburized toachieve the desired depth in the flank. This requirescarefuJ modeling of the diffusion of carbon in themasked region, as the carbon profile could becomevery flat due to inward diffu ion, A more elegantmethod would 'entail. a partial oxidation treatment inthe root region to, reduce the carbon intake in thatregion. If the controlled fonnation of Cr203 or even. orne type of 5i0'2 could be encouraged in the sur-face of the root region, thenthe influx of carboncould be controlled to achieve the dual case depth

tooth, Till in turn, limits the maximum contactstresses developed. A deep case depth, which is spec-ified to willistam:! high contact load , is therefore notnecessary if tho e load cannot be reached by thebending properties of the gear. At the same time, a

suggested.Inve ligation imn novel heat treatment technolo-

gies hould a1 0 be considered, especially ill the li.ghtof the work. carried out by Davies and associates at theWesl.land Helicopter Corp. (Ref. 43-47) dealing wilhduplex 'treatments. It shoald be pointed out that in themanufacturing of ease hardened gears, the benefitsexpected from the best engineering practice and thehighest level of accuracy do not materialize if the flee-essary metallurgical input into gear production isnotgiven the necessary attention and emphasis. 0R!:ferencesI , Johnsen K:l., "CO!l1llC! Mechanics." Cambndge University Press .1.985.2. Howe, MAn.."Mcllllll!tgical Suucture and Gear Performance,"G~aT ManufacfrIf! and ~ifontlOJlc~. ASM. 1974. Materials Park,OH.3. Alban l.E., "Failure of Gears." Metals Handboos; ASM. MaterialsPark:. OH.1988,4. Peterson R.E . "Stress 'Concentration Factors," Wiley. 1974,:5, Smilh J,O. and Liu Cheng Keng. Trans. ASME Series E, J. Appl.M~ch.. June 1953,6. Johnson K.L.. Proc. I:nsm. Mech, Engrs .. 1989,i, Breen D.H.. "Fundamental Aspects of Gear StrengthRequirements." !lGMA i'!lblkarion 229.17. ovember 1974.Washington. D,C.8. Lewis w.. "Investigations of the Strength of Gear Teeth," Proc. of(II~ Engrs Club of i'hilad~lphitJ. 1893,9. Dolan TJ, and iE.1. Broghammer, University of Illmois.Experimental Stauon, Bullt'fin No. J3S. 1942.10, Aida T. and Y. Terauchi, Bull, of th lSME. 5. 11. 1962,II. Andrew J.D., J. of Strain AJlalysis,~"OJ. 26. n. 3. 1991.12. Hahn G'.T..and Q. Huang, "Rolling caract Deformation of 1100Aluminum Disks," M~r, Trans A September 1986,

13, Hahn G:r .. V; Bhargava, C. . Rubin and X. U:Dg. "Analyse ofthe Effects of Hardened Laymon. Rolling and Sliding ContactPerformance," Proc. Int. Cont on Carburlsing, Processing andPerformance. 12-14 July 1,989. Lakewood. Colorado. ASMPublication, Materials Park, OH, 1989.14, Bhargava V" G,T. Hahn and C.A. Rubin, "Elastic-Plastic Analysisof Hardened Layers in Rims Subjected to Repeated RollingComacts," M~l. Tram. A.l&A. May 1987,15, PalTish G .. "The Influence of Microstructure on the Properties ofCase-Carburized Components". ASM Publication. 1980. M!!u:riwsPark. 01-1.1.6.Kem R,F .. Mel.Progres,f. July 1972. pp.53-M.17, Kern R.F., Met, Progress, November 1968, 1'1',60- i3.1.8,Sieben CA. D.V. Doane and DR Breen, "The Hardenahility ofSteels." ASM Publication. Materials Park, OH, 1977,19. Krauss G., "The Relationship of MlcrosU'UCtl!re to FractureMorphology and Toughness of Hardened HYpen!u!ectoid Steel "Case Hardened Steels. Microstructural and Residual St"'5, Effects.TMS. Warrendale, PA. 1984.20. Pacheco J.t.. IUId G. Krauss. "MlcroslnlclUI'e and High BendingFatigue Slrenglb ill Carburizing Steels," Proceedings of 'ht Int. Corrj.Carburlsing, Processing WId Performance, 12-14 July 1989.Lakewood Colorado, ASM. Materials Park, OH, 1989'.2L Zaccone M.A., I.B. Kelley and G, Krauss. "Fatigue and Slr.!ln-Hardening of High Carbon Martensite-Austenite CompositeMicrosrructures," PI'OC, aJ Heal Tm:un~rll 87 ConJ., 11Ie MetalsSociety. England. 1988.22, Zaccone M.A. and G. Krauss, "Fatigue and Strain Hardening ofSirnulated Case Microslnl.cturcs in Carburised Steels," Conf. Pro. oflhe 6th rill. COllgress on Heat Treatment of Marerial~. Heat Treatmentand Surfac Engineering; New Technology and PracticalApplications. Chicago Illinois. 28-30 September, 1988.23. Zaccone M,A,. B.J, Kelley and G, Krauss, "Strain Hardening andFatigue of Simulated Case Microstructures in Carburised Steel:'Can! Proc.. Carburi:sing. Processing and Performance, 12-14 July1989, Lakewood, Colorado,24. Hombogen E., Acta Melallurgica, '19i8.25, Parhams M.A. and R. A. Fournelle. J, of H~I T~aring. Vol, 2.Number I. p. 54. 1.981.26. Razi m c.. "Some Facts and Considerations of Trends in GearSteels for the Automotive Industry," Can/. Proc . Allo}'s fl,r the 80 'sMeetillg. A..1I..1IArbor, Michigan. June 1980,27. Cavallaro G.P .. R.N. Strafford and 'f.P. Wilks, "Contact FatigueBehaviour and Case Depth RequLremel"!ts of Carburised Gears,"Proceedings of th Second Asia-Pacific lmemadonal Ccmfuem:e anMaltriais Processing, Singapore 1995.28. Cavallaro G,P . T.P. Wilk~.C. Subramantan, K.N. Strafford, P.French and J.E. Allison, "Bending Fatigue and Conl:!!.CtFatigueCharacterisrics of Carburised Gears," Proceedings of the SecondAustralio Imematlonal Conference on Surfau t,"8ineering, 7-,10March 199

_-----------O&.A------------Bedllner 'Charts

and Gear InspectionQ&A is your interactive gear forum.Send us your gear design, manufactur-ing, inspection or other fiefated ques-tions, and we '/I put them before ourpanel of experts. Questions may bemailed to Gear Technology, P.O. Box.1426,Elk Grove Village, Ii 60009,USA,faxed to {847} 43Ni61S or sent e/ectTon-ically to [email protected] expanded version of ll&A is alsoavailable at www.geartechnology.com.Hundreds of questions have alreadybeen posted and answered. Visitors are'welcome to post their own answers.

Doub!e R,nk Gill TUllng/

Smgl. "'.nk G.ar Tonini!

Me-aslJre-s V'iinltionl in e.nter Distance MiUIJ:t1i' Rbtlltu)rllIl Motion.

Fig.11 - Types lit com,I'0sita gear iinspectioll' ..

u..IV V)\I ..

III:V. v..

I 1\, IJ: ,..... T - ,'\ ""..,. iii,... J .\. J ,.,u

V 'V"'" - ..v v- , . ., ,. .. " ..Tootl1Numb ..

IFig.2 -Stri,p thin ,otdoubl. Uank compolil.test.

Robed E. Sm'ithis the principal in R.E. Smilh &

Co., gear consultants ofRoehester; NY. and one of GearTechnology's technical editors.HI! ha oller 50 years of experi-

tinct! in gllaring and is Ihl! authorof numerous {JtIpersandanlcles.He: is also very active in AGMA

standards development.

2.4 GEAR TECHNOLOGY

Question submitted byRamiro C. SalinasCo.rpus Christi Army DepotCorpus Christi, TX

Q:What are redliner charts.and whostill does redliner charts?

Answer submitted by:Robert E. SmithR.E. Smith & Co.

A: For marty years, the terms "redliner" and "red line charts" have beenused by the Fellows Corporation in rela-lion to the:ir line of double flallk com-posite testers, For example, they madeIlle No.4 Fellows Fim~-Pllch Red Linerand the No. 12RL Red Liner. Doubleflank composite gear inspeetion isshown chematically in Figure I. Theseinstruments were in such common usethai. the term "red liner" became syn-onymous, w.ith double flank compositeinspection,

The tenn "red line charts" apparentlycame from the facl that early recordersused pens that wrote with red ink. Thesewere a constant maintenance problem,diue to dogging and spatter. Laterrecorder u ed thermal writing pens andpaper, thermal array printers. or evenprinter attached to PC computers.Double flank composite testers are madeby many different. companies and can usea variety of writing methods that do notproduce a "red line" on the chart.

To compound the confusion evenmore, the 'term "compo ite' inspectionhas been taken to mean double flankcomposite inspection beeau e it was insuch common use. As can be een inFigure I, there is another type of com-posite inspect jon, called single flankcomposite, tilat can be used. Today, bothtype appear in gear quality standardssuch as AGMA and ISO.

Double and single Hartle compositetesting results in charts such as thaishown in Figure 2. However, they meancompletely different things, As Figure Ibows, double flank composite test

measure center distance variation as thegears mil Ihrougb light mesh. Singleflank composite testing, however, mea-sures rotational motion variation, as thegears roll thrilugh mesh at standard cen-ter distance. with backlash.

One can see that the continued use ofthe term "red liine chart." is not a verygood idea. The terms "double flank com-posite chart" or "single flank compositechart" would be more accurate and pre-vem confusion as to what the data mean .

The 0000

There's only one way to ensure th.atthe gears you. produce will always detiversuperior and quJet performance. MU'e surethey're bred from quality stock.

Dura-B~ continuous-cast gray and ductileiron performs like free-machining steel with animportant. added bonus - quieter 'ope"atio'D.

Lik.e steel. Dura':Bar 'can be austempered,through-hard,ened, Dame-hardened, or Inductscn-hardened for added wear resistance. But thesuperior noise and. vi.bration damping characteristicsof Dura':Bar make for quieter runninggears. An,d Dura-Barjs 10% Ughter than steel.

Dura-Bar round. bars are available in diametersranging from 518" to 20" and lengths of 6-20'. So youwon't need to make major changes in your machining equipment.And our extensive inventory means Dura-Bar is avatlable now - when you need it.

When U's, quality material, quiet performance" and quick delivery that count, look to'contlnuoua-cast Dura-Bar for your gear productson needs.

Continuous Cast fron BaT Stock:Contact UI for the late.t data OD ,gearDolae.

1800BARMlLL (227-1l455].' 8153381800 '. RaJ:: 815338-15492101)1West Lake SIl.ore Drive. Woodstock. IL 60098-749~Web, Site: wII/'w.durabar.com .' Email~ , [email protected]

CIRCLE 158

_----------IHIEATTREATlNG, SER,VlICES, DIRECTOR,Y _Welcome to the 1999 Gila, rechnolDfY Helt Treating Directory. Use the lim below to identify complnielIccording10 the kinds at heat treating services

the, provide. Complete company comet information cln be found in tile Company Indax section on page 41. G , Technology advertisers.reshown in bold-flCII type. To find the pelllll on wIIich th.ir Ids .ppe.r, se, till Advenil8rs Index on pag .....

While we hi.mede lin" effort 10 ensure that complny names and addf81181 ". comet. WI' clnnot be held respDlllible for errors at fact 1M' omillioa.Hyour company wal not lilted in this directo", and you would like to ba included in the naxtona, plee .. cIII(847)437-6604.

FIND WHAT YOU'RE ILDOIC1NGi FORAGE HARD~N IN G_ " .., _ _ ,.P.26ALUM INUM JREATlNG __ _._P.25ANNEAUNG _ _ _ _ _ _ " _P.25AUSFORMING _ _ _ _ _ _ ..P17AUSTEMPERIN G _ P.27BLACK 0){IOING P.27BLAST CLEANING " P.27BORONIZING P.27BRAZ1N G P.2JCAAQONITRIO ING_ _ _ ..P.28CAABURJZ1NG _ _ _.P.28CRVa !lEN ICS _ _ uo" P.28DIE nUENCHING P.30FLAME HARDENI,NG P.30mEE o.UEN CHING _ ~ _ ...... _ _ __ P.30HOI 01 L OUENCHING _ _ _ _ _ ...I~30INDUCTION HAAOENING _ P.31ION NITAIDlNG P.31LASER HAROENING P.31METALLURGICAL TESTING P.31NITRJOI NG P.34NfTROCARBURrZlNG .._ " P.34NORMAlIZING " _ _ _ _ _ P.34PlASMA CAABURlZING .._ _ _ _.P.35PRESS o.UENCH ING ou _ __ P.35 ,SALT BATH NITRIDING P.35SHDT PEfNING P.3551NTERI NG P.35STEAM TREATlNG _ _ _.P.35STAAl GHTENING _ _ _ " P.35 'STRESS REUEVlNG P.35,T(MPERIr.lG P.36

I VACUUM TREATING P.38OTHEA HEAT TREAT SERVIC~S P38HEAT TREATING !EQUIPMENT AND SUPPLlES P.38

AGE ,HARDENING mIDI] Heal 1'"=...lIDgA.F:C. - Pirro Fhune Melllls Processing

dvanoed Thermal General Heal TreatingTechnologies, Inc. General Metal Hear

, Alliance Metal Tnm~ng ire4tin.s lnc.AlPha Hear Treaters Gibson H~l Trea!American Brazing Grund Rnpids CommercialA.merican Heat Treating Heal1'rellting Co.AIl:erican Me!aI 'IlmJingloc. H & S Heat TreatingBeehiVe Heat Tn:nung Hansen. Balk Steel TreatingBenedict-Miller Hanni Ricl!mond Inc.Bennett Hear in:aling Hindcdirer-AnaheimIkJdycoo: S.W. Inc. lillCdl Metallurgical Co.lIOOycoo: Thermal Iii-Tech Sreel Treating Inc.

~las Hnrizo!! SI11'relI!ing Inc.Bod~ Ilx:mW HasllwEb & Swn Co.

Proressing~1'l. WC!I1f1 Houslon flameffilrderungBodycote Thermal !-ITCl Commercial

~ng (Willi!) InductionBurbank SIl:eI Tn:nting IITG Hitech Aero DivisionCen!'ml Kentucky Hudl!pack-.Elkbom

Processing HIKW_---{;knda!e H1ll.Cermuy Sun Metal "J1reating [ndustrial Metal TreatingCerti1icd Metal ernrl Indi!...maJ SII. Tteanng Icc.CincinruW Steel Treating Iooex, 10(;.City SreeI Trealing Irwin AU!O!I!aliooInc.Coleinan OlTreating Inc,Geo, It .PoI1cr Steel

Treating Co.Gibson Hear Treal Inc.(;Jeason PrilLlei' H!!rtb

'Cutting ToolsGr.md Rapids COIllIIlemaIHeal '1'rw.ing 'Co.H &; M Meti! I"rocessingH &; S Heat TreatingHansen-Balk Steel TreatingHnuni R:ichmood Inc.Heal Ireat Corp, of

AmericaHQI Treating ~HI TeeMetal, Group

-ClevelandHinclertitelHeaI T!eaIln.g IDe.

-AnabeimHindel'li"1cI; Heat'Ii1:aIin!! Inc.

-DmlasHindcrtl1cr HeaI.1l'I'caIing Inc.

-TarzanaHirKbliIcl; Heal 'Thl:iJ:ing Inc.

-TUlsaHi(och MctallllTgical Co.Hi-Tech Steel Treating .Inc.HoriL.on Sll:el TIeatiog Inc.Horsburgh &; Sax! Co.HTG Commercial

loductioo

lITO Hitech Aero DivisionH!Idapa.ck-EIkhomD~~JmdMHb;.Hydro-\I3cHyVaI: T~ Inc.Il!iana Heat Treating Inc.lmpaal SlnllcgiC'l Inc.lnduclioo Meial Treatinglnduction Services Inc.:lnducltiheHtlnc.htduslrial Melnl TreatingIndusttilll SIeIl11'real:ing Inc.lcona,lnc.i.l'OIlbolind Heat "IreatingIIwin Automation Inc.Jw;oo Heat 'Treating Inc.JCS Engioeenng &

o.,..'elopmell!Joim V. J>oo:ro Co.Kowahli Heat 1treating 'Co.LW County Sll:el Trel!dnglawrence Industries Inc.Lindberg HBm Treating Co.

---;BerlinLi.ndbeIl! Heal. Treating Co.

-HoustonLindberg Heat Treating Co.

-M~Pwt II..inc:Iberg Heat Trea...1ingCo.

ew BerlinLindberg Heal Treating Co.

-RacineI..indl::Je!i Heat Treating Co.

-RosemontLindb;:tg Heal Ttea....ting Co.

-SllouisM & M Heal. TreatMagnum Metal T:rea!lngMl!S!eI" Hear Treating rOC.Meril Gear Coql.MeIlll~ICo.

-ColumbusMetallInpI:ovcmml Co.

-Lafayelll!Meta!' Improvemenl Co.

-McLeanlWicllil/!Mel;!]MeihodsMetal Treaters Inc.Metal Treating Inc.Metal T""l

-- .HIEATTREAnNG SERVllCiES mRECTORYllI _I'Iulo ProdI!cts Co.

ashvilk:Paulo Proo:IucIs Co"

~ l.n!W.PmmyIVllllia temllwgii:alPrIm: Heal lieaI:ing IIIc.PI!oe.nix tkal Tn:ar.iog Inc.Pi!l-Tc.>I. Inc.P=ision HClI T~~ve S!eell'mui118RIItiDe Heaal'rel!ling 0.Ril::hlcr P=ision Inc.Rochesler' 1eC'1TreatingRoIaIiro Prod!!C!S Corp.S.KoS. Heal 'fR:aIing Inc.Sctll fulgeShore Mew TechnologySoIarA~ Inc.Sana: HealT~g Corp. ISou!hcaImI 'Ma!:I1i1ay Co.

aI.iooaI Meml Proi::Essinll'1'a!!Ia Ptnducls Co. .

-' CiI)'I'lIuIo Pnxb:Is Co.

--MurIm:sboro,1'tIocniI< Heat r-realinglnc.Sooce Ueal TreaIlI!l! Corp.Sou on Heal TreatingSIttl~Inc.

IlIII:'OO>I 'HJ!8I. Th:at. Inc.

Tteating Div.W=idc Ramo:Haroerung

,BLACK~IDJNGl\.F' - Pi1coAbboo Furnace CompanyAdvanced Heal Thating Ioc. IAlco H_ Treating Corp.AIpi!I Hea! Irea!m~-Mi..llefBmneu Heat TreatingCenlraI K.enwi:ky

~l1g~.,,!!!gII!'II

Dmoit Slttl Treating Co.EImi.a Hear Treatin !nc.,Gibson Heal T~H!wm Rtdunood Inc./:Ii- Tedl Sftl Treating Inc.Horizon Slttl 'freaIing Inc.~ SIflIIcglo Inc.II1riIoond f!dI ~ng

I Jasco lInl Tn!atinzlnc., Mldwestt:mM~ Co.

P!!uJo Prnduct.; Co.-Kansas Cify

PanIo '1i'ItxIoru Co.

l'IIuIo Pn:lducIs. Co.-SLl..JJui~

Sl!perior MI:IaI T=ting)TIICIlS He:I! ~1Il!

"I'bero1!!I MeIal TreaJingUniver.w.l Heal TreatingWe..

HEATTREATINiG SEiRV1CES DIRECTORV _

&dyro!e 'I'hertnaIProcess-illg-DalJas

Bodycote ThermalIPnxessinll-FI. Worth

&dyt:oleThenmlProcessing (West)

Bmddock MetaIl.wgicalBraddock Mctllliurgical

-AlabamaBrite Metal '!'mating Ioc,BUfbaok Steel Treating, IDe.CalDoom Dh,il.ionCaroI:in.a Commerciol HealCaterpillar Industrial

Products Inc.Centr.lKentucky

ProcessingCenIW)' suO etaI Trealing ICertified Heat Treating Inc. IClncinnati Gear Co. ICincinnati teel TreatingCity Slll'reating IDe.Coleman CQfI1mm:ial Heal

TreatingCommercial Sleel Treating

I Delavan Steel TreatingDetroit S"",I Treating Co.Diamond Heal1'reating Co.OWe Real Treating Go.OWe Machine & Heal

Treating !nc.Drever Heat TreatingDynami.c Mew! '!'matingEaseLind tkal Tie;!!EasI Carolina Metal

'Il'ealing :Inc.EdWards H~t TreatingElmira Hent Trealing Inc.~ Heal Th!at IDc.. IErie SfeCl1'reating Inc.Euclid Rent Treating Co.Falr&ld Mfg. Co.FeinblaQld~g LId.Flame Mewls :I'rocessmgPPM Heat Treating

-Elk GrovePPM Ipsen Hew:TreatingFPM MiIwI1uk:eeFranklin Sled Trealing Co.General Heat T!e;.ltingG:nernI ~ Heal

Treating loc.Grand Rapids. Comrnerc.ial

HC311Teating Co.H& S Heal lI'W.liDgHauni Rid!mood Inc.Heal Treat Corp. of

AmericaHeat-Trearin Inc.H! TecM~!al GTOI.!P

--ClevelandHinderli.ter Heat.Treating

loc.-AnahcimHinderliter Heal Treating

1Jx:.-DalhisHindeili1er Henl Treating

lnc.- TarzanaA.P.e. - Pifco HinderiiICt' Heal TreatingAbbou ~ Company Inc.- ThIsa -

, ABS MetaIlu:rgicaI HiTecb SICcl1iil:Wng Inc.ProcCSSOOl me. Horizon Sleel Treating Inc.

Accurale Steeli Treatillg HTG Com.merciaiAdvaooed Hel!l Treating Inc. InductionAdvanc.cd Metallurgical Hudapadk~khom

Technology Huron Mel1lllu:rgical III\:.Advanocd Thermal llIilma Heal Trea!inglnc.

Technologies. loco Impact S!m!egies Inc.Albany Mellll Th:lIting loduclion Metal TreatingAlcetcrs Hent Treating Inc..Phoenix Heal. Treating locoPrecision Heal1'rcatingProgressive Steel TreatingRacine Heal Treating Co.Rochester Steel TreatingRotation Products Corp.S.K.S. Heal Ttelliinglnc.~ Mew! TedmologySoo:lheasu,m Heat TreatingSpecialty Hem Treating Inc,

-A.lhetlSSpecl!!lly Heal 'Im!ting Inc.

--BkbartSpecillJty Heat Tte:llinlllnc.

-Gr.md RlIpi~ .Specinlty Heal Treating Inc.

-HollandSpeciall)' Stecl 'Jlrw.ing loco

-Fannington HillsSpecl!!lly Su:el Treating loco '

-FfIISeI"SIlIIC Heat Treat Inc.Steel Treaters, inc.Su:cl TreatingSu_ Heat'Iia:.~ Inc.

--ClriruxIoSuncoas.t Henl Treat. loco

-':Pompano BenchSullCQ!!S! Heal TIel!!. Irn:.-Tampa

Superior Me131l'realingSyracU!ie Heal Tn:ming

T. . Woodworth 11K.Tberm Tech or Waukesb!l,Thermal Mellll Treating Inc.Thermal Treatment Center'Ibe!mo EIe!:otx1 Metal

'i=lingDiv.Thermo Treala'S LId.Tractech Inc.T\'eal All Metal...s Inc.'Truu:c indlIStriCSUniversal Heal TreatingWashillll'oo Mew!lurgtcai,

ServicesWeiss loousmcs Inc.

A.F.C. - PifcoAbboIl.Fumace CompanyASS MdallurgjcaI

~Inc.ccurate Steel TreaJing

Advanced HeaI.1'reatingAdvanred Mew!lwgical

TedtoologyAdvaoced The!maI

Thcbnologies. Inc.Albany Metal TreatingAlee Heat Treating ,Corp,AIllam:e MeUll TreatinB-

Alpha Heal. Treaters IA.merican Heat Treating Inc.Acmeriam Metal l'nIcessingAIIx:rica!l I\1eiaI T!ef!!lng Inc.Al~WestsboreBeebive Heat nesting [!\C.BeoedictMiLler Inc.Berme!t Heat TreatingBodycote S.W.lnc.BodycOle Tbermal

Proces.mlg---,OallasBodycote ThennnI

Pto!:es.'lIDll'-'PL WorthBodyCOle Thermall

Processing (West)Borro.ak Corp.The Bowdil Co.Braddock MetallurgicalB.rndOOck MewlIwgical-~Brite Metal nesting Inc.Burbank Steel Treating Inc.Cal-Doran DivisionCarolina CoinJ:neocilll Heal

TI'eatingCale!pilliu- Industrial

Products Inc,Central Kentucky

i'n:x:t:ssingCentwy Sun Melal T~.J:ingCertified Heat Treating Inc.C~MetalCIlIftCincinnati Gear Co.Cincinn.ati Steel TmltingCity Sleel Treating Inc.Clearing NiagaraColeman Commercial Hcal

TreatingCommercial Steel TreatingCu lorn Heat Treating Co.Delavan Steel TrealingDetroil Steel,Treating Co.Di3lllOl1dHeal1reating Co.Dixie Heal Treating Co.Dixie M!lChine & HMil

Treating locoI>reer Heal TreatingDynamk: Metal Trea.J:ingEasz CaroLina Metal.

Treating Inc.EI!s!Lind Fleal Trea!Eckel Heal TreatEdwards Heat l'reatingEJmim Hcal 'Il'ealing .!nc.~H~n.U;IC..Erie Sleel Treating loco

Euclid Heal Treating 'Co.FairtIcld Mr~, Co.Feinblanking Lid.FenlOO Hen! Tn:ati!!!l,Flame Metals Processing,Fox Steel Jl-ealing enPPM Hen! Treating

-Elk GroveFPM Ipsen Heal TreatingfPM MilwaukeeFnmklin Steel Treating Co.Gear Company of AmericaGeneral Heal T!eatingGe-~ral MctaI Hea!

Th:lIling Inc,Goo. H. Porter Steel

1iutingCo.Gibsoo Heal 1'reaI loc.'Grand Rapids ~IHeal Treating Co.H &. S Heat TreatingHllnsoo-:BaIk Steel TreatinHal!lli Richmond I!!e.Heal Tie;!! Corp. of

AmericaHIll!I1'reaJjn.g Inc.mTecMe!al Group.

-ck:~landI HindcI'I.W:r .!:IJ:aI1realing Inc.

-AnaheimHio!trli!er JbTreI!!i!!g h.

-DallasHio!trlirer HeatTreaIing 10;:.

-ThrzanaHinddli~ Heal ~.loc.

-TuhaHi-Tech Steel Treating Inc.Horizon Steel Treating Inc.Horsburgb &. Scot! Co.lITG Commercial

InductionH-!I!II!p!IC.k-EIkhomHuron MelalJurgicalloc.Illiana Heat Treating!nc.1mpooI. Stmtcgies Ioc,induction Metall'renlingIrd:isuial Mew! i'reaIl!1glodu....mw Steel Treating Co.Industriall Steel Treatiog .Inc.Ironbound Heat TrealingIrwin AlliomaJ.ion Inc.JaKO Hsi 'l'mlting Inc.I..alw County Steell'reatingLawrence [ndusrri.1lli Inc,Lindberg Heat Treating Co.

-BdJin .I...i:lxIDcrg Heal Treati:ng Co .-HooSlOO

Lindq Hen! Treating Co.-Melmse Park

Lindberg Heal Treating Co.-New Berlin

LindbergHeatTteating Co.-Racine

I.indbeq Heal ~ Co.-Roches~

Lindberg Heat. Treating Co.-iRosemonl.

Li.1!!lbetgHeal im!!ing en-SI.J...oois

M & M Heall'renlMagnum MelallW!!ingMII5~ Heal Treating 'loc.Merit, Gear Corp.Melalln1pmvel'!lCl!l Co.

oll!lllbu.!lMe!!!llmprovemenl Co.

-LafayetteMetallfi\prov"ment Co.

-McLeanlWicbitaM.i!taI Th!aIers Inc.Metal Trea.Jing Inc.Metal Treating &. R=bMelallurgicallnc.Metallurgical ProcessiogMewh Engint.ering JI.::Mc!aIs TecbnoqyMe~lIbCo.

Melro S!=I. TreatingMel-Te:k Inc.----ClackamasMelTek Inc, - acineMidland Metal1'rea!ingMidwe~m Machinery Co.Modem Indusmcs locoMountain MetallurgicalNational ,Broocll -National MetaiProccssingOakland Metal ireati:ng Go.Obio Melailu:rgical Servia:P & LHem Treating &.

Grioomg.I'an:ek LI!bom!O!ies Inc.Paulo Products Co.

-Ik,-

1HIEATTREATilNIG SERVICES mRE,CTORV 1American Cryogenics, Inc,American Heal. Th:orlil!gA=rican Mcral'l'rea!ing Inc.Applied Cryogenics me.Beehive Heat Treating Inc.Benedic!-MWcr lac.Bermett Heal TreatingBodyoote S.W. inc.Bodyeote 1lIermaI

Processing=DallasBodycore Thermal

Processlng=-Pt, WorthBmddock Merall!!JgicalBraddock Metallurgical

~A1abamaBurbank Steel Treating Inc.Cal-Doran DivisionCarolina Commercial Heal

TreatingCenmry Sun Metalli"ealingCertified Heal Treating iIIc.Certified Metal CraftCincinnati Gear Co.Cincinnati Steel TreatingCily Steel1'reatinglnc.Delavan Steel TreatingDetroit Flame HardeningDeiIDil SreeJ Treating Co.Dictie Heal TreatingDrever Heat Treating

, Dynamic Metal TreatingEasl Carolina Metal

TIea!ing Inc.East-Lind Heat "fiealEdwards Heal TreatingElmira Heal11reaJing In!;.Engineered Heat Treat Inc.Erie Steel Treating Inc.Euclid Heat Treating Co.Fel:LI.oI1 Heat TteatingFlame Metals ProcessingPox Steel Treating Co.FPM Heat Treating

-Elk GroveFPM Ipsen Heat TreatingFPM Milwaukee.Gene!aI He.11Treating .ox1"General Metal Heal

Treating Inc.Gee. H. Porter Steel

Treating Co.Gibson Heal Treat Inc,

1 Hansen-Balk Steel TreatingHauni Richmond Inc,Heat-Treating IIIC.Heat Treat Corp. of

AmericaHIThcMetal Group

-OevelruxlHLnderllter !ieal1il"eating Inc.

~AnaheimHinderliter .Heat 'l'rea!ing Inc,

~Dal.IasHinderliter .Heal1il"ealing Tnc..

~Thnana .

Hirnedirer Heal Trea!ing Inc,~Thlsa

Hi-Tech Steel Treating Inc.Horizon Steel Treauug Inc.aro Commercial

tnductionHTG Hi!edl Aero DivisionHudapack~ElkbomHydro-VacHy-Vac Technologies Inc.

, Illia!!I loouslrial Srecl Treating tllC.Ironbound Heal TreatingIrwin AUloma.r.ionInc.J!!SeQ Hea.t TheatinlllDc.Kowalski Heat Treating Co.Lindberg Heal. Treating Co.

~BerlinLindberg Heat Treating Co.

=Houston .301 GEAR TECHNOLOGY

Lindberg Heal Treating Co.--Melrose Park

Lindberg Heat Treating Co.-Racine

Lindberg Heal Treating Co.-.Roserno!J[

Magnum Metal TreatingMaster Heal Treating Inc.Metallmprovemenl Co.

~olY!!)busMetallmprovemenl Co.

~Mcl..canlWi.chilllMetal Treaters Inc.Metallurgical Inc.Metals Engineering: Ioc,Metals TechnologyMetlabCo.Metro Steel TreatingMIlI.-Tek Inc.--Ch!!;:kamasMidland Metal TreatingModern IDdustries Inc.Mountain MetallurgicalNitrex Metal Ted!oologies

mc.~BurlingtonNitro- Vac Heal TreatingOhio Metallurgical ServicePaulo Products Co.

-"B==rPaulo Products CO.

~Kan.'II\S CityPaulo, Products Co.

~MempbisPaulo Products Co.

-MutphreesboroPaulo Products Co,

~NashvillePaulo Products Co.

-St.LouisPenna Flame Industries Inc.Pennsylvania MetallurgicalPeters Hoo! Treating Inc,Phoenix Heal Treating Inc.Pitt-Thx Inc.Prog!e.o;siveSteel TreatingRacine Heal Treating Co.Rochester Steel TreatingRotation Products Corp.S.K..S. Heal Treating Inc.Shore Metal TechnologySolar AlrOOSpheres IDe.Sonee Heal Treating Corp. ,Soo!hea.M Mllwaukee

I Franklin Steel TreatingGenem! Heat TreatingGeneral Melal Heal

Treating Inc.Gibson Heat Treat Inc.Hansen-Balk Steel

-- ------------,

.. HEATTREATINiG .5E:RVIICES DIRECTORV _l'renr.ing

Hauni 'Ridumnd Inc.Ileal Tmil COli'. of

AmmcaHeal. T:ren.Jingino:;.H! TC(;MdI!.! Group

-Clevelandlfi!!derltla" tkalT~

ino:;.-TuIsaHi- ThdI Sled Trca1in8 IJx:.tbizo!l S~I ~ Inc.Kar--Cleveland:I-fIG CommerciAl

IndUC'liO!!I.onc:l. Inc.Li:ndbctJl Heal. Treating

Co.-RoscmmtIMagnum Mellll TreatingMP'iAroericaProgressiV1: EngillttringSOOT I\I~ Inc.Sane!: Heal1l:mir\g Corp.Sun Stotl ifr

.'

F,roml your singlesource fo,r'compult.erized.analytica'il and function'al'gaging systems, Gear-Net'" server automaticalty

shares data. for SPC, remoteanalysis and archiving.

Simple familiiar interface ideal formanufacturing cell operators.

Unmatched software selectio.n,including bevel gear machinecorrecnon package.

Pentium- based technol.ogy. Complete training and applications

support wilh every system.

3506 Series CNCGearManufacturing Process, ControlSystems offer full four-axis flexlib:illtyandunsurpassed accuracy..Certi:ficatio.nto..ommm traceable to.NISTand probe

___ resolunon to .OOO02mm, Vou getgreater productivity, to.o"with upto.20% faster throughput andcapacities to 95" in diameter.

260 Series Systems provide ali! theperfonnaace and dUli3Jbility of the largersystems, but in a compact size that'sperfect for high production parts up to.10" in diameter.

....' ' ..' .

.-.-.''.

'GRS-2,Double-Flank Gear RollerSystem comblnes proven performancewith easy-to-usePu compatible sofrwareto make inspection accurate and simple ..Total composite, tooth-to-tooth andrunout tests determine if parts coaiormto specification. Computer analysis letsusers specify AGMA or DIN tandards,

I then determine the class of gearachieved.

Dimensions Over Pins 'Gage measuresactual tooth thi.cknessat the pitchdiameter. A unique constant-pressuregaging head assures repeatability andaccuracy over the full range of the gagingsys~em whil:e greater throughput allowsyou to inspect moreparts and reduce----production costs,

Other M&MPrecision Systemsinspe-cCtion p.roduw:'. Master Gears'. Spline 'Gages'. Variable Spline Indicators fixture Gages Arbors

Free brochure Call 937/859'-8273or fax 937/8594452.

PRECISIIINIIYIITEMIIt:IIRPIIRATIIIN

"THE Mel ROLOGY& MOTION PEOPLE"CIRCUE 140

_---------HEATTREAT.IING SERVICES DIRECTORY.I ..Hudapack-ElkhoroHuron Metallurgical Inc,Impact Strategies Inc.InduJ>1rUUSteel Treating Co.InOO trial Steel TreatingIronbound Heal TreatingIrwin Automauoe Inc.Jaseo Relit treating Inc.Kowalski Heal Treating Co.Laser Machining. Inc.Lindberg Heal Treating Co.

-HoustonLindberg Heall=ting Co..

-New BerlinLilldberg Heal Treating Co.

-RacineLmdbeq: Heal Trea!ing Co.

-RochesterMeril Gear Corp.Metul lmprovement Co.

=-ColumbusMetal Treaters Inc.Metal Treating Inc.Metallurgical Inc.MellabCo.lIfelTel: lnc.~lHckllmasMichigan Induction Inc.Midland Metal Treating0& W Hea!1h:aIInc.Pennsylvania MetallurgicalPhoenix Heal Treating Inc.PiIl-TelIC Inc.Progressive Steel TreatingRacine Heal Treating Co.Rieliler Precision tne.ROO/tion Products Corp.SoneeHeat Treating Corp.Specialty Heal Treating

=-Grand RapidsSpecialty Steel TreaiingInc,

-Farmington. HillsSpecialty Steel Tn:ating Inc.

-FraserSyracuse Heal TreatingThermal Me!ServicesWeiss Industries Inc.Westside Flame Hardening

INITBID.INGAbbon Furnace Companysccorure Steel Treating

Advanced MetallwgicalTechnology

Nbany Metal TreatingNco Heat Treating Corp.Aruaican MotaJ 1rea!inglnc.Benedict-Miller Inc.Beanett Heal TreatingBodyeote S.w. Inc.Bodycote Thermal

Processing-DallasBraddock MetallurgicalBurbank Steel Treating Inc.CaJ.-Dor.m DivisionCaterpillar Industrial

Products Inc.Cenlury Sun Metal TreatingC~Lnt1ati Gear Co.Cincinnati Steel TreatingCity Steel Treating Inc.COllI!llerciai Stee] TreatingCustom Heat Treating Co.Drevet' Heat Treating

~~I~Z;:tting ITreating Inc.

Eh:oirn Heat Treating Inc. I