Useful Grinding Information

7/29/2019 Useful Grinding Information

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~7~Introductory

In preparing this booklet the aim has beenthree-fold: to show how certain operative featuresdistinctive on our Universal Grinding Machineare used to advantage; to aid those confrontedwith grinding problems about which they areoften unable to obtain all the necessary informa-tion, that they may use the Grinding Machineprofitably and efficiently; and to assist those notfamliar with grinding wheels to a right under-standing of them, with the hope that it will proveof service to OUI' many friends.

Special effort has been made to treat eachsubject in a clear and comprehensive manner,carefully avoiding al unnecessary matter.Wedonot show inthis booklet our complete

line of Grinding Machines, which includesDuplex Interna, Surface, Disc, and CylindricaGrinding Machines.

If the booklet does not contain certainexplicit information you want, or if you havegrinding problems of any kind causing difficulty,never hesitate to write us. We have specialistswho are always ready to assist you in devisingways and means of economcal grinding, andtheir suggestions may prove of value.'It is a pleasure to acknowledge the many

courtesies received from Grinding Wheel Man-ufacturers, and the valuable informationfurnished by them on grinding wheels, in prepar-ing this booklet.Universal Grinding Machine Co.

F itchburg, Mass.


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THE TABLE iswel proport.ioned, and like the cross slidethoroughy seasoned between operations. Itisprovidedwith aswive plate for ~rindng tapered work and hasa scare grnduuted in inches per foot, and degrees.THE GRINDING WHU:L HEAD is of the most rigd con-struction and has ony a vertica movement. The whee spin-dleismade of tool "lee. hardened and ground, anc! run", inlargeadustable phospaer-bronze bearings, thoroughy protectedfrom W-it.. The screw which feeds tbe whee bead verticalyis graduated to 1-16"andsprovided with amcrometer readngto one-thousandt.h of an inch.TIlE HEADSTOCK haa a dust-proof swive base, accurateygraduated. The o;pindlcismadeof stee hardened and groundand runs in adustable phosphor-bronze buarings. Thespinde revolves for chuck and face-plate work, and isarrangedto be locked when grindng on dead centers.THE FOOTSTOCK SPINDLE is provided with a variabletension spring, controlled by a handwbce and Quck actinglever. The spinde may be clamped rigidy for suPportinthe center to the work.THE TABLE IS CONTROLLED by adustable dogs, operatingaganst the reversing lever, which actuates the clutch of theload and fire type, or by convenently located hand reversinglever, which provides means for stopping the table at the endof ita traverse automaticaly. by giving the lever a part of aturn at any time during the traverse of the table.THE AUTOMATIC CROSS FEED FOR CYUr-;DRICAL

GRINDING operates at each reversa of the work table, andcan be set. to reduce the dameter of the work from .00025"to .005". The feed is automaticaly thrown out when thework has been reduced to the requred size.THE AUTOMATIC SURFACE CROSS FEED operates atether. o r b0t..hj-eversas of work table - .THE CROSS SCREW I1ANDWI-IEEL is provided with a stopfor duplicating work.WORK AND T~AVERSE SPEEDS are independent, and can beinstantly changed while runnng.

Side and Rear View of Bath Urriversa Grinding Machine


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The Bath Universa Grinding Machine Arranged for SurraeeGrindng

Surface GrindingThe cut at bottom of page shows our SurfaceGrinding Attachment, as furnished with the BathUniversa Grinding Machine, and is shown attachedtomachineintheabovecut.Theattachment spindleisscrewedonto themainwhee spindle through which it is driven. The arm

which carries the outer bearing is clamped to thegrinding wheel head, the alignment being insuredby tongue and groove. The outer bearing is sef-aigning, bengcarriedby aswive head.

Surface Grinding Attachment


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Fig. 1 shows cross section of grindingwhee head on our No.2 and 2~ GrindingMachine.To adjust wheel spindlebearings: Removedust screws AA and loosen tapered screws BB which/~;~:~{~: L ; : ~~

1 '- - " t=-Z f L - I H +l - I '!,:u~~7.:: :G

Fig. 1take the place of liners, aso loosen nuts ce. Thentighten nuts DD which draws tapered bearings in,when bearings are properly adjusted screws BBshould betightened, then nuts ce and replacescrews AA .To take up end thrust of whee spinde loosenscrews E and F. Then tighten up screw G, asoscrew F. when the proper adjustment is made,clamp collet firmy in place by screw E.Fig. 2 shows a section of cross screw adustablenut on our No. 2 and 2% Universa GrindingMachine.To take up lost motion innut, loosenlock nut Aand draw nut B out until proper adjustment ismade, whennut Bshould belocked inplaceby nut A.


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. ,.- ...-..,JISharpening Large End Mill

Use cup grinding whee.Swing knee to 90 degrees, or right angles towhee spinde.Cutter is held by taper shank in Universal WorkHolder. The Universa Holder is set so as tobring center of cutter in line with axis of wheelspinde, this beng insured by dowe pins.Set adjustable center and adjust jaw to mllshank so that mill revolves freely without shake.The proper clearance is obtained by tiltingV block the required number of degrees which isread direct fromdia.Clamp High Tooth Rest on swive plate andadjust finger so as to bring cutting face of toothonthe sameheight as center of mll,H o l d cutter agai nst too th rest f inger w hengrinding.Use tooth rest finger for indexing also


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(

Sharpening Periphery of Inserted MillingCutterUse cup grinding whee.Swing knee around to 89 degrees, thus allowingclearance on the "upside" of grinding whee.Cutter is mounted on an arbor and held inUniversal Work Holder. The horizontal Swiveland V block being doweled on zero insures the faceof cutter being ground absolutely straight and atright angles to side of cutter.The tooth rest is mounted on wheel head,finger being set over cutting point of wheel and oncenter of cutter.The tooth clearance can then beobtained etherby raising whee head the desired amount, whichcan beread fromelevating screwdial. or by tiltingthe V block the desired nurnber of degreeswhich canbe read direct from vertica dia. See table onpage 34 for clearance.When grinding, hold cutter against tooth restfinger, and becareful not to run cutter off ot finger.


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Sharpening a Counter boreUsedish-shaped grinding wheel.Swing knee around to 90 degrees.Counterbore is held by shank in Universal WorkHolder. The Universa Holder is set so as tobring center of cutter in line with axis of wheelspinde, this beng insured by dowe pins.Set adjustable center and adjust jaw so counter-bore revolves freey without shake.The proper clearance is obtained by tilting

V block the required number of degrees which isread direct from dia.Clamp hightooth rest onswive plate and adjustfinger so as to bring cutting face of tooth the sameheight ascenter of cutter

- ---~..ul'lIC I,;ULL~ oe


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left inplace and ~wivel head swung around 90 degrees.T he sw i v el h . '. .

u sinsuring the periphery and side of teeth being groundabsolutely at right angles.

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Sharpening an Angular CutterUse cup grinding wheel.Swing knee to 89 degrees which allows clearanceon the "upside" o C wheel.


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Sharpentng a Taper ReamerUse cup grinding whee.Swing knee around to 89 degrees, which alowsclearance on "upside" of grinding wheel.The reamer is hed between head and footstock

centers.Swive Plate is set to the proper angle. Tbis

cannot be accuratey obtaned by reading scaeaone, but must be determined by repeatedy tryingthe reamer in astandard taper hole.Clamp high tooth rest on swive plate and

adjust finger above the center of work the desiredamount to give proper clearance on tooth. Seetable on page 34 for clearance.

When grinding, hold reamer against tooth rest! i n ~ e l , a n n U ~ Ql i n e ~ rt o ; n ~ e x b y .


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\-= 1[

- ,Sharpening aGear Cutter

(Using Specia Gear Cutter Attachment)Use dish-shaped grinding wheel.Thekneeisswungaround to 90degrees.Thegear cutter attachment ished inUniversaWork Holder.The cutter ismounted onstud of attachment.Set cutting (aceof grinding whee aganst gauge,

this insures the teeth beng ground radialy.Set cutting faceof cutter by the gaugeequa to

the amount of stock desired to be removed, thenadjust tooth rest against hee of tooth and clamp inplace.Feed grinding whee into cutter by traversehand wheel.When grinding, hold cutter against tooth rest.


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Corundum wheeshave beenvery success-ful in al classes of grinding and especiallytempered stee. . .Emery isa natura abrasive, obtained frommnes in India Brazil and Massachusetts, and con-tains a large pe;centage of non-cutting elements com-posed of amorphous alumna, silica and iron oxi?-e.which gives emery grams their dark color, crystallinealumna being the only element In emery hardenough to have any appreciable cutting action onmetas. The grains are tough and have a roughsurface which provides excellent hold for the bond,alowing whees of great durability to be made.However. few grinding operations require suchdurability. Wheels made of emery are usedmostly for the grinding of stee bals and on workwhere a very high finish is desired.Aloxite isan artificia corundum manufactured by theCarborundum Company, and in its crude formis taken from eectric furnace in the form of largecompact ingot or pig weghing severa tons. Thispig consisting of crystaline aumna is crushed togran form by means of specia machinery. thenrefined, dried and graded, when the grans are thenready to bemade into grinding whees.The characteristics of Aloxite are its purity.hardness, sharpness, toughness, absolute uniformtyin quaity, and it has in addition a temper whichmakes it idea for grinding stee. .It not ony cutsfast. cool and clean, but it shows wonderfu durabili-ty, and has been extensivey successfu inal classesof stee grinding.Alundum is an artificia abrasive, manufactured bythe Norton Company, and is made by fusing inthe intense heat of the eectric arc furnace, Beauxite,a soft clay-like susbtance. Beauxite is the purestform of aumnum oxide.In chemca composition Alundum is simlar tothe ruby and sapphire, and the physica formationis such that when it is broken it leaves sharpcutting corners or edges.Alundum characteristics arehardness, sharpness,and temper or character of fracture, which makeit ahighly efficient cutting materia for the grindingof stee.Carbolite is an artificia abrasive manufactured bythe American Emery Whee Works. It isextraor-dinarily hard and sharp, and while not tough.as compared with other abrasives, its very brittle-ness makes it most efficient for certan grindingoperations.Carbolite whees are used for the grindingmaterias of low tensile strength, especialy castiron, brass, rubber and leather.Carborundum is an artificia abrasive, manufacturedby the Carborundum Company, and is distinctfrom anything found in nature. The principa


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with certain other materias, the Silicate ofSoda isadded and the wholemass thoroughlymxed together in specia machines. Thisforms a pasty mxture, which is thenrammed into moulds. Only experiencedmenarealowed to do this work, as the uniformty andbaance of whees depend largey upon the skill ofthe moulder. After the whees aredried they arebaked inspecia ovens at amoderate heat. Silicatewhees are light gray in color.The advantages of Silicate wheels are: Wheel3can be made in a week. As no excessive heat isused, the abrasive grains possess all their originalstrength. \Vhees of any SIze can be made up tofive feet in diameter and over. Whees may bemoulded on iron centers, which cannot be done withVitrified whees. For wet grinding the soda in thebond has a favorable action, as it causes the wheeto cut smoothly and with little heat.The disadvantage of the Silicate wheel is: Inthe harder grades silicate whees are generaly notas freecutting as Vitrified whees because they aredenser.Silicate whees are especialy adapted for wetgrinding on hardened stee. For wet tool grindingand wet surface grinding (particularly when cupwhees are used), they are unequaed. They areasogood for wet cutter grinding and some kinds ofcylindrica and interna grinding.Elastic Process: Elastic whees are made from amxture of abrasive grains andshelac. For makingvery thin whees this mxture is rolled into moulds.Thicker whees are ether moulded under hydraulicpressure or rammed into moulds the sameassilicatewhees. They are baked at a temperature to setthe shelac. Elastic whees arenearly black incolor.Advantages of El",tic Process: Wheels as thin as1-32 may be made and used with safety. Thereastic quaity makes them very smooth cutting, sothat if properly graded for the work they give afinefinish, whether usedwet or dry. They can bemade quickly, and can be moulded on ironcenters.The disadvantages are: Elastic whees will notstand much heat. They are less open and porousthan Vitrified whees, and they cost a little morethan Vitrified or Silicatewhees.Elastic whees are used chiefly for finegrindingwherenogreat amount of stock isto beremoved, orwhere a very thin whee is necessary. They arewel adapted lor dry cutter and reamer grinding,wet tool grinding, saw gummng and cutting ofsmall stock.From the foregoing it is evident that whees of anyabrasive materia may bemade by anyone of theabove described processes for binding the grains


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required. because the grans, will break awaymore readily. thus presenting sharp pointsmore often.Use a whee one grade softer for castiron than for soft stee. .Coarse Whees: Use aC?&!se whee for reducing thestock rapidy, where finish 15not Important. Thelarger the grans the deeper the cut that may betaken and the less liable the wheel is to clog and glaze.A coarse whee properly dressed will produce agood finish. . .Complaints are not uncommon that grinding wheesappear to be sorter towards the center. U~ualythis is because the same surface rate of speed IS notmantaned as the whee is reduced in diameter.This causes the whee to wear away faster andappear softer. To obtain the best results therevolutions per mnute of grinding whee mustbe increased as the whee wears down, so as to keepapproximatey the same surface speed of grindingwhee per mnute.

For Surface Grinding, a softer bonded whee isrequired than for externa Cylindrica grinding.The Jarger the surface of contact between thewhee and the work the softer should be the whee.Thus. asofter whee isrequired for surface grindingthan for cylindrica grinding. Conversey, aharder whee should beused for work of very smaldiameter than for larger work. and a thin wheeshould beharder than athick one.A loaded whee is one whose face has particles of themeta beng ground adhering to it, which is causedby the whee running too slow or beng too hard.A glazed whee is one whose cutting particles havebecome dull or worn down even with the bond, andis caused by the whee running too fast or bengtOG hard.

TRUING OF GRINDING WHEELSGood results cannot beobtaned with whees which areeven slightly out of true. In cylindrica grindingthe work shows chatter marks and a wavy ap-pearance, and in al cases of grinding the finish

IS poor if the whee is out of true.In tr-ui ng and dresstng the grinding whee thediamond should be firmy clamped to the table,and the diamond traversed rapidy by the face ofgrinding whee until it is true, this will leave theface of the whee rough and in proper condition forrough grinding. For asmooth finish the fina passof the diamond across the face of the whee shouldbe very slow. and for extra fine finish the cuttingface of the wheel may be slightly glazed by holdingan oil stone aganst t.heface oC whee for amoment.It is important that the diamond point presented tothe whee should besharp. this is accomplished by


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Work andTraverselfthe best results aretobeobtaned, carefu atten-tion must begiven the seection ofwork and traversespeeds. Often wben Ialure t? produce, goodresults is attributed to the grinding whee, Itmaybe remedied by changing the work and traversespeed or work; as, for instance, if the whee speedis

correct and work is running too fast the whee willglaze and give the effect of a harder grade wheel.Then too the work and traverse speeds govern, toa certain extent, the kind of finish obtained.No fixed set of rues can be lad down for theproper seection of work and traverse speeds.Different conditions, as kind of materia, amountof stock to be removed, desired finish, grade, gran,materia, and speed of whee, etc., al vary the re-quirements; hence, wegivenoabsolute instructions.

The Work Speed recommended for stee is 15 to 25surface feet per mnute for ordinary work, athoughon avery hard and tough stee better resuts will beobtaned with slower speed for roughing. Forfinish grinding the speed shoud be increased.The work speed can be somewhat increased (orcast iron: 25 to 35 surface feet per mnute givinggood resuts in the most of cases. Use a higherwork speed for finishing than for roughing.The Traverse Speed of the work for roughing steeshoud be about two-thirds the width of grindingwhee per revolution of work, and for cast ironshoud be slightly less. For finishing, a verynarrow traverse per revolution is required.

Broady speaking, for removing stock use aslowwork speed and fast traverse; viceversa for finishing.\Vhen finishing cast iron pass the work over thewhee as few times as possible, as the whee will beless liable to glaze..

The depth of cut to betaken depends upon the whee,materia to be ground, and amount of stock to beremoved. Where the part to be ground is rigidenough to stand a heavy cut, the cut shoud be ofsufficient depth to alow the whee to do its utmost.Grinding to Shouder: The best method of grindingwork with a shouder is to feed the whee in to thework at shouder to within .0005" above size, thengrind the baance of work. This will leave edgeof whee next to shouder sharp.Water upon most work is absolutey indispensable,and shoud be used wherever possible, exceptwhen grinding bronze, and some classes of Internagrinding. Water keeps the wheel clean and freecutting, and prevents the generation of heat,which causes the work to get out of true.


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Dont'sDon't try to grind al materias with the samewhee. It is economy to get the right gran andgrade for the work.Don't mount whees without soft washers

between the whee and the flanges.Don't force whees onto the collet. It is liableto cause breakage. Enlarge the hole sothe wheewill slip on easily.Don't use a whee which is not sound. Thiscan be ascertaned by tapping light.ly and listenfor a clean ring.Don't start work on a new whee until you aresure it runs true and is in baance.Don't attempt to true whee without first seengthat diamond ished rigid.Don't start to grind until you know the speedis right.Don't crowd a whee on the work. It will notcut any faster, but will simply heat the work andwear out sooner.Don't destroy the tags onthe whees, keep themfor reference and re-ordering.Don't try to grind with a whee that is loadedor glazed. pass the diamond over 'whee afew times.Don't use a bet of uneven thickness to drivethe whee.Don't hesitate to ask usany questions pertaningto grinding machines and whees. There will benocharge.Don't forget to change speed of whee Spindleaswhee wears down.Don't run agrinding whee at a greater numberof revolutions per mnute than the manufacturerrecommends.Don't move head and footstock before thorough-ly cleaning swive table.Don't alow dust or grit to enter oil holes.Don't forget that soda water keeps the workand the machine from rusting.Don't put work in machine until centers andcenter holes in work have been carefully clamped.Don't forget that we invite correspondencereating to grinding propositions and difficulties.


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,TABLE OF GRINDING WHEEL SPEEDSDiameter Rev. Per Minut eRev. Per Minute Rev. Per Minute Rev. Per MinuteWheel for Surface Speed for Surface Speed ror Surface Speed [or Surface Speedof 4,000 Feet of 5,000 Feet of 5,500 Feet of 6,000 Feet1 inch 15,279 19,099 21,000 22,9182 " 7,639 11,4593 " 9,549 10,500" 5,093 6,366 7,350

7,6394 3,820 4,775 5,250 q,7305 " 3.056 3,820 4,200 4,584" 2.546 3,183 3,500 3,8207 " 2,183 2,728 3,000 3,2748 . . 1,910 2,387 2,600 2,86510 " 1,528 1,910 2,100 ~29212 " 1,273 1,592 1,91014 " 1,75016 . . 1,091 1,364 1,500 1,637955 1.194 1,300 1,43218 " 849 1,061 1,2731,15020 " 764 955 1,050 1,14622 " 694 868 950 1,04224 " 637 796 875 95526 " 586 733 800 87928 " 819546 683 7503Q " 509 637 700 764

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TABLE OF WHEEL GRADESABRASIVE Wheel CO. AMERICAN [,Wheel Co.Oegrree PROCESS Ileeree PROCESSof Vi/rifled {Sillcale Elast of Vitrified SlIlcale /asf/c/iorclnes s HardnessVerrSo/t .----. H ---- -.I v,,~Sofl .. 0 ... - 1,;1 -- - "'2 E ', Il;, H % 0/4 EJ Z , 1 1 ES o f t .----- K ------ - - z i> Sofl ...J .. "'I~ .- - 1'2 EL 3, K Z Z ENed/II"" .. ---- M ------ - 3:.': L 2 ', 2~EMedfvm N 4 /"fed/11m .. M-- .. 3 .. . 3 E..---..0 ------ -. 5 H 3', 3~EHar d p 6 /'fed/11m a 4 , 4 EHar d "-- - Q ------ - ? liard _.. P .. . _ . 4 ;. . '2 . - -41ER Q 5 5 ES R S ' f . Sl,.o![Very Hard ----- T Very#ol"(/ ..- S .. - - -6 6 EU IT 1 1 EV Uw .drem>lr W

X --- YExtremel!l y Hard ZHard .. ---- Z

CARBORUNDUM Co.lJ e;ree PROCESS0 / Vill"l j Jed! Sil/cole E/aslt~flartll1essVenjJ/erf .... -- Z ......Soft y 13X 12i/er!lSojl .____w ------ - "' 0U 9So/I .. - .. - T _ . - - - - .. 8S 7l1"d,v/17 R 6Soft _.. _-- P - -- - -0 5Hl-1edltlm _____ M -- -- . .4LK 3l1~d/ll1l J

Hora ----.I - - - - - - . 2I.H ,MIford ---.-- G - - - - - - - '< zOKF 'EYe,.vlloN' . .. .- 0 co"


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TABLE OF WHEEL GRADESSAFTY Emery Whe.l C O . STERLING EmeruWhe.1 C O . VITRIFIED Wheel Co.Degree PROCESS Ot>fI"PP PROCESS Oe~ree PROCESS0/ Vi/rtffea' Silicole 0/ Vdrified,! Stile-aIR Elaslic 0/ Vd";fi~dISilictlfe ElflsticHar dnes s Hor.(ne5S !fardtte55

ExIra So/I __ C __ --6 V"!lS1' ____.4 ______ -I Soft ------c --- --- t o ~c~ S}.l " 1 J . .1 . Z C'V,'ySo/I - - H - - --5 r1 -4 C' r} EH) z Sf/' - - - - - z - - - - - 3 c ' 2 ESoft ---A -- ---4i Z j , /'{"d/vl11 - - - - 0 - - - - -2.!-lEA~ Heel/II'" 1 4 -3!z Sojl 0' 3 [A~ Sofl -..---1/~---- 0' 3}-. EA\ 0' 4"[1'f""A/ So/I -M -- --4 Ned/11m ----- 3 ---- --4 H"Ii/vlf1 ----- [ ----- -4!zEM~ [ ' 5 [M!'-z 3~ E' 5~M~4 Mealllm --.. ---- -41 E' 6 Hed/vm ---p -- --31 Him 37l Hord ----- F - ---- 6"-[P~ F " ' 7' [P ..! - l 3~4 5 F " 'P~4 HIII~d ----- ---- Ex.lrem(J /Y f3l1etl/vlfI No,.tI -I ----3 4 6 ----GI Y 4 Hord1 ! . . - 2 51~4 ---2~ V"yH.,.J -----Hard --0 -- 6O~4" O~ ZVer~/lord O~ - _ . J ' !' - z .-- ".

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TABLE FOR SELECTION OF GRADESAND GRAINSABRASIVE MONARCH NORTON co.Kind0/ Naterial MATERIAL GRINDINGToBe Cround. co . co . ALUNDUM CftY 5TOlOINCraifl C r o de Cl'dlit C r o de C r a in C r a de Cntl" S rad .~~y,~~~g~irj",IIit 2 ' .,- ". D Y .' 6 " )&30 , z~~~~~~"2-"J i7""ir-" 2'>' 9 . - ; . 0 'V z. 3. , , , > J~ 0 38361~~~~~U~ir""l;" Z4 l E- 6-!(, R I'k 3. I '/z.' 6 J 3830~R/~~;r~~~fJ:;';6 K ~8u , " - 3036 , , , >10. M 0 3830 a z~"~~~nl:111~~~,~~ J ~ U IV z. 3. l'i10. L 3836~!J'~~!C~:~~6 J 8-~R Iv,. 3. 1\ .''2100 L 3830l,~~!~~; ; ' / : , : 1 ; 1 1 ' 30 ? ( 1 - 1 2 . lYz J 3. K60 M 3846CAr,T IRON PULlY, Z, L 8 31 ./z. K 36 Kt""d,.;ca/ (lrl"di " N 3836~~~Z,''j;!~hl'~~L.I:D '1 . - r z : to ! J 3' JE 3846~~S~~Fl~~s~~~L.!-ED J 6. J3860

3 -~S ~! c!5!~rd/17 J6 K 8 z J 56 J60 M 3836CAST IRON J 6 J , & , loZ1~ J 36 JhtllPrl'll1; C,.;~d"" O. K 3846~.,; : ~'! .~:dJ i r " J 3 . Jl83~~!!~~~s.~~~.o1~1 J " ' , R J70 M 3860Ic : . .U i J l ' ; ~ S ! .; - S t : t : : ! ., L " . , 0 K0 N 3850KNI\lES- HARD ' 0 , 'V . 2 . I'A Jc Whee' 60 M 46 K~~ l J /~ : .ac : !~':(I' 6. L " JN 3BSO KREAMERS . 6 L 'X z 23- 4. WAe,I 6. NRUQ8R J , , * J 4 . Jluul,./ctll CrlMJIr L 38+6f!I~:~r/~A,,?TJ : ': ;d'iru6 L Y, ,3'4 K M 50~r;J;.~~!~~..36 K 21}h J0 L 3846l~ fE . ) ; ;J J : f 9 . . , , , , _ , , , , J . K ~l~" J6' L aasc5TI..- HA.RD. Smal l , J , 2V, : ; 846 Jnfe,."DI G"/,uhir 6. L " 2Yl.STtEL-HARD.""!Yif? , J 6 J ~ 9 ZV2. . J"fer,"," (),.i/'fd', 60 L 3846~~~~~;~AJ 'r~ndi" J 6 % 1]4 H L 38465T~EI..-HARD J 6 K ~ J, sc (iI"""";' 60 M C 3846? r ~~~: .J cO !l C " " 'd". 6 M~ ~II ZY:L L60 ,'h ' 0STECl-SOFT,S","''', 4. K , 2Y2. 3846 Knfel"lflll Crl; ,dln 60 M

",~~~OJ ,.,l; ;J ~e. 'I . '\ ' 1 "" K6. M 'V , 3846~~; t L& -"~~~d,;"~ ' 6 L - S a J M 2'1". 38361 l f _ E l G , . ~ ; ; : ' h a . 6 L ~-II U J. M 3846~~%~I il/"", M 9 - ~ 1 3rt J 38461.~::~;~~~ 6 L 2-% . u K60 N o 38S0~'~!~!i~.,~I~~d;"6 L , Z .. K M "

2


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Front View of Bath Unversa Grindng MachineA Brief Description of

Bath Universal Grinding MachineTHE BATH UNIVERSAL GRIND( to MACHINE has beendesigned for t.he purpose of combinng in a singe maehineefficient means for the grinding of Cylindrica. Interna.Surface. Disc, Cutter and Reamer work of al descriptions.In thismachinei!lincorporated al theessentia features necessaryfor performng the various grindng operations with as muchrapidty and accuracy as coud be accomplished on a singepurpose machine. It is so designed that the chan~n~ofmachine from one operation to another is reduced to amnmumTHE BASE of tho machine is a singe massive casting, on top ofWhch is pprmanent.ly boted a vertica coumn of liberadmensions; interna~y ribbed, and having a circuar flangebase as large as th top of machine base. To this VerticaColumn is gibbed te grindng whee head, thus supportingthe grindng whee head by a heavy wal of meta drect UI thefloor, and having ony onemovable joint between thc wheehead and base of machine.THE CROSS SLIDE K..'lEE, which een-ies the cross and longi-tudna slides. bas a very large circuar base that fits overthe etreuar base or the vertica column which provides abearing of libera dmensions for the knee to swive on, the

kneebeng swung around th9 column to bring the work tabtein proper reation to the whee for the various operations thismachine is adapted for. The knee is graduated in degreesand can bereadly clampedat any an,;lefrom 0to 90 degrees.THE CROSS SLIDE whch provides means (or feedng the workinto grindn~ whee, and carries work table and operatin~mechansm 19 substantialy ribbed internaly and of liberadmensions tbrougbout., It is thoroughly seasoned betweenmachinng operations to insure aignment.


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The Bath Unversa Grindng Machine A~ranged for InternaGrindngInternal Grinding

The cut at bottom of page shows our InternaGrinding Attachment, in detal, as furnished withour Universa Grinding Machine, and is shownattached to machine in above cut.The design of this attachment secures theutmost rigidity inoperation. The arm isaparabolaform of massive proportion, is bolted firmy to theside of tbe column near its base, and is self-aligning.The interna spindle is driven from a pulleywhich is clamped on the nose of the main wheespindle.The interna whee spindle ismade of tool stee,hardened and ground, and runs in adjustablephosphor-bronze bearings. thoroughly protectedfrom water and grit.This attachment is readily attached to machine,as can beseen by astudy of the two views.

Interru.l Grinding Attachment

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Unversa Work HolderThe Universa work Holder adds greatly tothe variety of work possible to be ground on ourUniversal Grinding Machine. It is of speciaLvalue for holding inserted tooth mills, counterbores,largeendmlls, reamers, etc., with straght or tapershank.By using Flange Plate. which is furnishedwith this attachment, gear cutters, flat formcutters,saws, etc., can bereadily hed.The Flat Vise also can be clamped to thisFlange Plate, which provides means for holding a.arge variety of work to besurface ground.The Cutter Bar Attachment is especiallyadapted for holding small end mills. angular andstraght cutters, etc., when a very sensitive move-ment isnecessary.

Cutter Bar Attachment;

8


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ctrrrsa GRINDINGOn the f?l1?wil,Utpages weshow how certan operativefeatu '!!S. detincttve on the Bath Unversa GrindngMachine:!!, are used to advantage in aharpenn cuttenreamers, etc. ,

. Wedo no~ attempt to cover the entire range andeapaety of themachine.The il.1ustrations shownwill suggest amethodof handing thegreat variety of other work that can bedone on this machine.'I'hemethod of setting up, as shown by these iUustrations, isnot ar~trary. Inmost. cases severa other waysof grindng thesame Piece ean be used.For surface grinding smal irreguar pieces of work clamp inflat viseand hold vise in ,,?nivensalWork Holder, the V block bengremoved and nl!-nge plate Inserted to receve flat vise.Beow we KJvea few genera sUgestions for grindng euttera~eamers! ete., inaddtion,to theexplanatory matter at the foot ofIllustrationsonthe Icllcwing pages.HINTS ON GRINDING CUITERS AND REAMERSShoud tbe grindng whee strike the tooth next to the one bengground, the wheel head should be rased until this tooth clears thebottom of grindng wheel.When grindng eearanceon the teeth of cutters, reamers, ete.always usea cup-shaped grindng whee,as this gives astraght laceto the land which supports the cutting edge 01the tooth. If adsc whee isused. the land will beconcaved.It is beee to revolve the grindng whee aganst the Cuttinl:edge of tooth, as it prevents a burr beng formed at the cuttingpoint. and there is lessdanger otdrawing the temper, thus enablingthe grindng to bedone :faster.Care must. be taken to hold, by hand, the work aganst toothrest, with auffieent. pressure to prevent its beng lilted by thegrindng whee.Clearanoo on the "down" or "upside" of grindng whee isobtaned by setting the knee onedegree err zero.,Vhen the tooth rest te stationlry and rk is traversed, careshoud be taken not to ean cutter 0(( of tooth rest..When grindng taper reamers, ere., aways clamp tooth rest toawive plate, as this grvcs the same clearance to the tooth through-out the length of the reamer.In setting for tooth clearance on mlling cutters, ctc., insteadof setting tooth rest above center, it will be found much quckerto tilt the V block on Unversa 'York Holder. and work carrier onCutter Bar Attachment, the desired number of degrees.The table on page 34 gives the amount to set tooth rest abovecenter of work to obtan proper ange of clearance 01\ mllingcutters and reamers,C

i f AWJBFig. 1 Fig. 2

Figs. 1 and 2 illustrate two methods of grindng reamers.Fic:. 1shows avery narrow land back oC the cutting edge; C equasabout .025" [or cast iron and .006" for stee. B equas about16degrees Ior cast iron and9to 14 degrees (or stee.Fig. 2 shows the method generaly U5Cd, the ange of eearancebeng from:) to 9 degrees. Different manufa,,[u~er'll reeommendvarious anges for cast iron, bronze and stee.

o

10


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Sharpening Side Teeth of Inserted ToothMilling Cutter

Use cup grinding wheel.Swingknee to 89 degrees which allows clearanceof "upside" of wheel.Cutter ismounted onarbor and hed inUniversaWork Holder.The Swivel Base is doweled on zero to insure the

side beng ground absolutey at right angles toperiphery of cutter.Tooth Rest is adjusted so as to bring cuttingface of tooth on same heght as center of cutter.The tooth clearance is obtained by tilting the

V block the required number of degrees to giveproper clearance, the degrees can beread direct froruvertica dia.When grinding!hold cutter against tooth restfinger, and use finger to index by.

12


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, 'I. 1

Sharpening End of Chucking or RoseReamerUse cup grinding whee.Swing knee around to 89degrees which alowsclearance on "upside" of whee.Reamer ished by taper shank inUniversa Work

Holder.Set adjustable center and adjust jaw to shankso that reamer revolves freey without shake.Set Universa 'Work Holder swive base to giveproper angle.Clamp high tooth rest stand onswive plate andset finger on center of work.The proper tooth clearance is obtaned by tiltingthe V block the required number of degrees.When grinding, hold reamer against tooth restfinger.Use tooth rest tinger for indexing.


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A ~I(

Sharpening a Special V CutterUse cup grinding wheel.Swing knee around to 89 degrees which alowsclearanceon "upside" of grindingwhee.Mount cutter on arbor and hold in UniversaWork Holder.Set Universa Work Holder to proper anglewhichcan beread fromSwive Base.Set tooth Test finger on center of work, and tiltV block the required number of degrees to giveproper clearance.'When one side of cutter is sharpened swiveUniversa Work Holder around to opposite angle.Set tooth rest onother sideof cutter.When grinding, hold cutter aganst tooth restfinger, and use finger to index.The cutter may be aso hed between head andfootstock centers Cor sharpening. In that case theknee isset to givethe desired angleand tooth restfinger set above center to give the proper toothclearance. Seetable onpage34for clearance.

J G


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Sharpening Small End MillUsecupgrinding whee.Swingkneeat right anglesto whee'spindle.Cutter is hed in Cutter Bar attachment, which

provides a very sensitive movement.The Cutter Bar swive head carrier is set so

as to bring center of cutter in line with axis ofwhee spinde, this beng insured by dowe pin, asotilt swive head to required number degrees to giveproper clearance on tooth, the degrees beng readdirect from vertica dia.Adust tooth rest finger so to bring cutting faceof tooth the same heght as center of cutter.Use the lever feed, and hold cutter by hand

against tooth rest finger. Toindex, revolvebushing.

18


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Sharpening a Spiral Milling CutterUse cup grinding whee.Swingkneearound to 89degrees, thus allowing

clearance on the "upside" of grinding whee.Cutter is held on an arbor between head and

rootstock centers. It is preferable to have thecutter revolve and slide on arbor as this methodinsures the cutter beng ground absolutey straghtandtrue withthehole.Use high tooth rest stand and set center of

tooth rest finger above center of work to give thedesired clearance. See table on page 34 forclearance.When grinding, hold cutter against tooth rest

finger, and slide on arbor, beng careful not to letcutter run off tooth rest finger.If cutter is pressed on arbor, thetooth rest standmust beclamped on grindingwhee head.

20


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Sharpening, a HobUse a dish-shaped grinding whee.Swing table around to 90 degrees or table atright angles to whee spindle.Hob ishedonarbor between head and rootstockcenters.The table is adjusted towards whee head untilIaceof grinding wheel is in line with work center, asface of tooth must be kept radial.The Low tooth rest is clamped on swive plate

and tooth rest finger adjusted so as to bring faceoftooth by the face of wheel, a distance equal toamount of stock desired to beremoved.TheTableshouldbetraversed by powerand the

grinding whee fed into work by the whee headeevating handwhee.When grinding, hold hob against tooth rest

finger.Use tooth rest finger for indexing.Nole- The set-up is the same for L arge Formed

Milling Cutters.

22


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Grinding WheelsThe operation of grinding asweknow it today,isnothing more or less than acutting process.The cutting tools are the sharp particles of abrasiveextending from the face of the grinding whee. Whenthese smal sharp tools are brought in contact, at highspeed, with iron, stee, etc., each sharp abrasive g-rancuts its own mnute chip from the work. These

chips resemble those removed by a lathe tool. Asthese abrasive grans wear or become dulled, theyshould loosenfrom the bond whichbinds them, alowingthe sharp points that are beow to be brought intoaction, inorder that the grinding whee may doefficientwork. If the points are retaned after they becomedulled, they prevent other sharp points fromcomng incontact with work, and the cutting action of the granschanges to a rubbing action, causing undue generationof heat that distorts the work, and prevents accuratework being obtained. While on the other hand. ifthe abrasive grans break away before they becomedulled, the whee isunnecessarily wasted. !From the foregoing it will beseenthat the successfuloperation of any grinding machine depends in a largemeasure upon the proper seection and use of grindingwhees. Frequently a change of grinding whee ormethod of using it will result in greatly increasing thequantity and quaity of the output. It is, therefore,important that al operators of grinding machines beinformed on this subject.The inexperienced operators of grinding machineshave come to regard the seection of whees as amysterious process dependent upon long experienceand good judgment. To a certan extent this is true,but in the man. the genera principles involved arenot difficult to grasp, and the time required is notexcessive.A gr-indf ng whee ismade up of two distinct kinds ofmateria, namey: the "abrasive" or cuttingmateria, and the "bond," which holds together theabrasive grans.Abrasive materias are of two kinds, natura andartificia. The natura abrasives are Emery andCorundum. The artificia abrasives are known asAdamte, Aloxite, Alundum, Carbolite, Carbo-Alumna, Carborundum, Carbondite and Crystolon.Corundum is a natura abrasive, found in Canada,India, Brazil and Georgia. The best corundumcomes from the Canadian mnes and contans 95%

of crystaline aumna. Corundum grans arelight in color, extremey hard, have a perfectfracture, the grans breaking, when dull, aongP I ' I [ ~ ~ ~ f r ~ ~ t ~ i i i t \ @ '~ f~ l i j ~ ~ i jm O ~ , i '~ ~ I ~ ~ \ I \ t ~combined with fast and cool cutting, the grainsbeing just brittle enough to break as soon as they

24

materias entering into themanufacture of car-


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borundum are crushed coke mxedwith sandThis ~awmateria isplacedinaneectric furnac~for thirty-six hours and raised to a heat between7000and7500degreesFahrenheit. At this tremen-dous heat the eements of carbon and silicon formcrysta masses. After these crysta masses coolthey arecrushed, washed, dried and graded. 'The characteristics of carborundum are hardnesssharpness, infusibility. insolubility, and just brittl~enough to break slightly in use. The sharp edgesof the crystals cut clean and fast, whileits brittleness,by constantly presenting fresh cutting edges,prevents glazing. It has proven highly successful ingrinding of cast iron.Crystolon is an artificia abrasive manufactured bythe Norton Company; is made from coke, sand,sawdust and sat, and heated in an eectric furnaceto between 1820and 2250 degrees Centigrade, whentheeementsofcarbonandsiliconformacrysta mass.The characteristic property of brittleness makesit highly efficient for grinding such metas as castiron, chilled iron, brass and bronze.The blndf ng togeth er of abrasive grains is nowdonebythree common processes, namey; Vitrified,Silicate, and Elastic.Vitrified Process-This, the most widey usedprocess for making grinding whees, consists inmxingabrasive grainswith suitable claysand fluxes.The mxture is then moulded into whees of therequired sizes, which, when dry enough are shapedand then subjected to a high temperature in largeovens or kilns. This mets the clays, which, uponcooling, crystalize about the grains of abrasiveand so bind them together. Vitrified whees arereddish or reddish brown in color, and have aclearringwhen they are tapped.The advantages of the Vitrified whee are: Thebond itsef is so hard that it acts as an abrasive.It isvery porous, whichmakes it freecutting. Theyareperfectly uniforminquaity and arenot affectedby water, acids, heat or cold.The disadvantages of the Vitrified whee are:It takes a month to make awhee. The intenseheat used in burning slightly weakens the abrasivegrains. Thin whees made in this way are notpractica, as they will break under side pressure.Very largewhees arerarey made by this process onaccount of the danger of cracking in the kiln.Vitrifiedwheesaregeneralythemost efficient forroughsnagging, genera shopuse, fordry tool grinding,for many kinds of cutter grinding, for cylindricagrinding, and for surface grinding when a discwheei s u sed .Silicate Process-The principa ingredient in thebond of silicate whees is Silicate of Soda, or waterglass. After the abrasive grains have been mxed

20

together. Thus, wemay haveaVitrified corun-


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dum wheel, a Silicate corundum wheel or anElastic corundum wheel. Ora de: The bond of. a wheel, in addition toholding together the abrasive grans, asodetermnesthe grade or degree of hardness of the cutting wheel.A soft wheelis one where the cutting particles breakaway very rapidly under.grinding pressure. A hardwhee will retain Its cuttmg particles longerDifferent kinds of work have more' or lesstendency t? wear away the wheel. Accordingly,wheels of different grades must be used for differentoperations. If the wheel is so soft that the grainsare torn away before the points have become dulledthen the wheel is wasted. If the wheel is too hardthe. grains will remain in place too long, i. e., aftertheir POIPtsaredulled, and the wheel will glaze overand cut slowly. The ideal wheel on any work isone that furnishes anew cutting face as fast as theparticles in use become dull; in other words, theproper wheel will not glaze, but will remain sharp.The degree of hardness or softness of bond isdesignated by letters of the alphabet and numerals.Each letter indicates a grade one degree harder thanthe preceding letter.On pages 35,36 and 37 are given tables of gradesused by different manufacturers.Grain and grade of grinding wheels should not beconfused. By the grain of a wheel is meant thefineness of the grains of abrasive used in making it.If the grains will just pass through a sieve havingsixty meshes to the inch, they are called number C O ,and the grain of the wheel is said to be number 60.N umbers run from 10, which is very coarse, to200 and flour.Combination wheels: Grains of different numbersare often mxed in one wheel. Such wheels arecalled combination wheels. A combination wheelwill hold its shape better and give a finer finishthan would a wheel made entirely of coarser grainsand will cut faster than one made altogether of thefiner grains. These wheels are used quite extensive-ly for the finishing of soft steel.Hard wheels: Unsatisfactory work in the variousgrinding operations is very commonly the resultof using wheels which are too hard. Such wheelsare slow in action, and generally produce apoor finish. They are likely to burn the work ordistort it and it is difficult to obtain accurate workwith them. Chatter marks, scratches and flatspots are commonly due to this cause. Wheelswhich are too hard (or the work require frequentdressing and are uneconomcal to use in every way.~ ~ ! tW n ~ ~ I ~ :w ~ ~ ~ l~ m ~ ~ t! ! i ~ i ~ n tl l ~ nu ~ t ~ [ te n o u g h n o t 0 w e a r a w a y l o o r a p l i l l y , T h e h a r d e rthe material to be ground, the softer the wheel


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revolving the diamond stud in its holders fromtime to time.The number of times the face of awhee hasto be dressed depends entirey on the kind ofwhee,andwork; Somewheeswear away fast enoughthat httle dressing 15necessary, onothers, especialyhard whees, and on large work when considerablestock has to be removed it,may be necessary. totrue the whee eacb time apiece receves its finish.A new whee that runs out considerably shoud betrued up at a slow speed and then increased toproper speed when it shoud be trued up agan, asItmay not run true at a high veocity, even if itdoes at a slower one.

SPEED OF WHEELBefore starting to grind the operator should makesure his whee is running at the proper speed. Itisdangerous to run wheels too fast.For Cylindrical and Lnter-nal grinding, the wheeshoud revolve at asurface speed of 5000 to 6000 feetper mnute. and for surface grinding about 4000 to5000 feet per mnute. As whees wear down thesurface speed grows less, and the number of rev-olutions per mnute of whee spinde shoud beincreased, so as to mantan the proper peripheraspeed.Increasing the speed of the whee makes it act likeoneof a harder grade. Decreasing speed of the wheegives the appearance of :l . softer grade.To determne the periphera speed of whee in feetper mnute, mutiply the diameter of whee ininches by 3.14 and the resut by the number ofrevolutions per mnute and divide by 12. Fortable of whee speed see page 33.

ORDERING WHEELSWhen nrdertng whees, particuar attention shoudbe pad to thenformation necessary for the wheemanufacturer to fill your order inteligently.Be sure to specify-Size of hole, Diameter ofwheel, Width of face, Shape No. (if special shapesend sketch), Make of Machine to be used on,Grade, Gran, whether Vitrified, Silicate or Elasticwhee, Kind of Abrasive.If you cannot definitey specify the grade andgran and last whee was satisfactory, send sample.

If new work, state speed proposed to run whee andwork, whether to beground wet or dry. send sampleof work or give complete description as to kind ofmateria, shape and size. machine whee is to beused on kind of finish desired, rd how muc~stock

01 uarauce.Third: The grinding whee is loaded or glazed~ J~m j~l~j ! m a t ~ r i ~ 1r O U n d having become


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e m ~ e Q d e d I n t 1 ~w ~ ~ ~ 1 ,Fourth: G rinding wheei too hard.

32


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Explanation of Tables forSelection of Grains and Grades ofWhees for Various Operations

The tables on pages 38, 39 and 40 give gradesand grams of whees, recommended by differentwhee manufacturers, for a variety of the morecommon grinding operations.These tables have been compiled more to givethe operator a starting point for seecting wheesfor. various grinding operations, than to specifydefinitey grans and grades of whees for certanoperations. Individua conditions will often modifythese; for example, the size and shape of work;size and speed of whee" the use of water orgrinding compound, or not; and the speed andtraverse of work. Then, too, al metas vary incomposition, as, for instance, the per cent. of carboninstee, and this variation will often "makenecessarya harder or softer whee than is generaly used forsimlar work. Finaly, there are the individuapreferences and methods of the user to consider.In some shops work is ground from the rough, inothers but little is left to grind. Some prefer rapidwork and medium finish, others require high finishwith necessarily slower production. Some demandvery durable whees, others look more for efficiency.Thus, it will be seen that no fixed rules can be laddown for the proper seection of whees, but bycarefully studying the characteristics of the wheesrecommended in connection with the result to beobtaned, the proper gran and grade of whee canreadily be ascertaned.By referring to the tables it will be seen thatAmerican Emery Whee Co., Carborundum Co., andNorton Co., each offer two abrasive materias. Forexample: The American Emery Whee Co. recom-mends whees made of corundum for cylindricagrinding on Alumnum castings, and wheesmade ofCarbolite for surface grinding cast iron; the Car-borundum Co. recommends Carborundum forgrinding cast iron, bronze, etc., and Aloxite for stee.There are two varieties of Alundum one ofwhich is known as No. 38, and to obtan it whenordering whees, "No. 38" should beprefixed to thegran number required. Thus, referring to thetable under Norton Co., for Surface GrindingAlumnum Alundum Gran e3830, Grade 1~ isrecommended; indetal would read Alundum No. 38Gran 30. Grade 1 Yz. El lElastic Whee.

KEY TO SIGNS USED IN TABLESC ; C om binati on w heel, grai ns o r diH erentnu m bers m i xed in one w heel .* =V i t ri f i ed W heel .e=Elastic Whee. -=o.

34TABLE FOR GRINDING CLEARANCE USING CUP WHEELDUlmeter D/S/OI1NI To Set rDI,/i1 HQs-l A~ye


37/40

f pr Below Work Ce/?ferevilerr nr'o For5 For 6 F or T O Fot" goHellmer C l e Qr t l n c e C'earan~eelf>o,.orrce Cteorance CleQrolue)/4 .006 .011 .013 .015 .020 .0 I 0 .016 .020 .023 .029Y. .013 .022 .026 .030 .039' " .016 .027 .033 .038 .049y ., .020 .033 .039 .046 .059V a .023 .038 .046 .053 .069I .026 .044 .052 .06 I .078lYe .029 .049 .059 .069 .088IY4 .033 .055 .065 .076 .0981%. .OJ 6 .060 .crz .084 .108I Y i .039 .065 .078 .092 .1181% .043 .071 .085 .099 .127Il< .046 .076 .092 .107 .1371 'Y 8 .049 .082 .098 .114 .1472 .052 .087 .105 .122 .1572Y4 .059 .098 .118 .137 .1772Y z .065 .109 .131 .153 .1962% .072 .120 .144 .169 .l163 .076 .131 .157 .183 .2353J, 4 .065 .142 .170 .198 .2553Yz .091 .I53 . I83 .214 .2753~ .098 .164 .196 .229 .2944 .105 .174 .209 .244 .3144Y, .116 .196 .235 . Z 7 S .3535 .131 .218 .262 .305 .392SY z .144 .240 .268 .336 .4316 .157 .262 .314 .366 .4706Y, . I70 .283 .340 .397 .5I07 .183 .304 .366 .427 .5498 .210 .349 .419 .468 .6289 .236 .asa .471 .549 .70610 .262 .436 .523 .610 .784II .288 .480 .576 .671 . .86312 .314 .523 .628 .733 .94113 .340 .567 .660 .794 1.02014 .367 .610 .733 .855 1.098


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TABLE OF WHEEL GRADESDETROIT [mer~ Whee CO MONARCH Grindi.~Whee Co.Oi?!7ree PROCESS IJ e9r,e PROCESS01 YiI."tj/t"l Sl/t:at~ DI Jlil/"'lji eJ S/J/ule /t7shcHo~d"ess I{flrti/,@SS

/ler 50/1 _______0 Ver!/5o/t --I'2 _E 11'4 ~ Ar Z I F "Sofl ------- G 2J ..4 1~4 III Z~l I~~ NI Sol' -- zJ /


39/40

AMER ICAN CARBOR UNDUM co.Kind ,,/ Holer/al [MER y W HEn co CARBO-To B2 CI'OUl1ti. C O R U N D U M CARBOUl( AlOXIT[ fWNOUMC r a in C rode C r t1 J n erade CromlCrade Cralll C rad e

~~,~~~~ Grind/" 54 t, / 0 2~!~4?~~~~"1-,...rd'iJn 46 I E 60 K 50 51~~~~~U~/;"dl;"D 80 IE 46 L 50 5~!.~J,..~:~~-;J4 M H M,~~~!"S~~"/~ 60 K 60 M~!o..~: :.!!:~~60 I E 4. L 40 MCA~T IRON.Small . 4. K 36 M 36 P. t",d,./c", (;,."'0';'CAST IRON PULLY. 36 L lOJ M"" d,.,Ca/ G l " l i f d l ' /r " Dg~~[o"~~~~~!LL.[O0 J 36 0 60 4CAST IRON CHILL.ED 60 2'1 80 12OLLS. ;':","$";"~!.~!c!2~"d'-"" 3 . M ,. R7h~~ ~,1 : J ~ " ; J 1d ' ; , 60 K 40 p~ ': - J :~~~diirD Jb J 3. L 3. p5-~J'!~:'~}.,~::~;:~,6 I ~E 50 N'i ! /S l ' : !S l :~-S{; :: ; f 4. I'/z[ 50 0KC~~~~~ARO J 6 ZE 365 MMlllS,Ftll'#, E"d 46 l ' i E so NondSia> C" W}lilci':-A;,,~~~ 60 K 40 0~~ /~i7'! - ~% al;1 '1" ' ' ' /; ' 4. M 40 M~TEEI..CASTING 36e L 3. M1/"".-/ al C,.;" d,;"~r;~ol,,~AJ !!~~6 J 36 05T(LL-~A~D. . 6' K 40 0""dr/el (;~ifdlrJ ; ~ :;; 'a 'jA R ( ) D ;. / ~ ; '~ 'j, 60 K 50 NSH.-HARD.l~P. 60 J 50 0l1fer,..,~"(;rfl,./f,.,Sll-~~;~~'\.~9;"dl: '6 J 365 05]/~s~LC~~:~-..,,,46 J 5o N~r~7t~ j c O : ? C " I " 'd l ; '36< L 24 t


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AND GRAINSKind " / /Voteri'1I1 DETROITSAfETY STERLINGVITRlnEDWHEEl co . WHEEL eo. WHEEL CO. WHEEL CO .roBe Gro vl T d. C!-ai" (If'll/iJ Qmd. r;'Di" Ct'dde Gnu'" en,do;rod.~~,~~:}i,.,it.flilq 36 4A L U M I N U M 46 3fnferna( C,;"dill1 L~ i !IN U M . . . 16 36 3fr Q~et;I"'ndlnBROHZE-BRASS 46 M ,,- I"\Y",- 30 3 36 Ez"-"dri~Qlt:;'itul.it!J z M9..0NZ&-BR~~S 4" P 3.- '\0 36 2 46 E,tC'"a c,.;" fA 70 ."~~~~!C~!'~6 J 46 M" ' - 30 2Yl. 24 f ,CA$T IRON.Smali. 46 K " MYl. 36 z 36 0,u/l"dn~o' Cri"d,;' A(,T IRON PULLY. 36 L l+ M'll 30 2 ' > 36 ,Clloitd";cal prindi", 3' P~~~(S.I~~qt~!~L.~O6 K " M Y z . 70 Z 46 z e4': ~~a:S ~~! ',: .r5,~~L J - E O~~r!"R~~,d"" 4" H 36 M 20 Z 30 0,6. M'l"CAST IRON. . 46 K " AY!- 46 1"

Useful Grinding Information

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