Itcoloy and M

illing Tools

ITCOLOY AND MILLING TOOLSInstruction Manual 5100

O n e C o m p a n y U n l i m i t e d S o l u t i o n sO n e C o m p a n y U n l i m i t e d S o l u t i o n s

ItcoloyGeneral Description ..................................................... 3Use ............................................................................... 3Construction ................................................................ 3

Milling Shoes and Rotary ShoesUse .............................................................................. 3Operation ..................................................................... 4

Milling and Rotary Shoes ........................................ 4Milling Tools ............................................................. 5

Maintenance ................................................................ 7Application of Itcoloy ................................................... 7

To New Tools ........................................................... 7To Rework Tools ...................................................... 8

Specifications and Replacement Parts .............. 10 – 11

I N

D E

XItcoloy and Milling Tools

The designs and specifications for the tools described in thisinstruction manual were in effect at the time this manual wasapproved for printing. National Oilwell Varco, whose policy is oneof continuous improvement, reserves the right to discontinuemodels at any time, or to change designs and specificationswithout notice or without incurring obligation.

Fifteenth Printing, September 2005

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General DescriptionBowen Itcoloy is a special hardfacingmaterial made of crushed sinteredtungsten carbide particles compoundedwith a resilient matrix of nickel-silver alloy.Bowen Itcoloy is made in rod form forconvenience of application whereveroxygen acetylene welding equipment isavailable.

In oilwell milling, when an Itcoloy hard-faced tool is rotated and lowered againstan object (that is, a fish, cement or for-mation), a multiplicity of small tungstencarbide particles imbed themselves intothe object. Each tungsten carbide par-ticle develops a small chip along theedge as it is moved across the object,cutting the object. As a particle’s cuttingedge becomes dulled, pressures andstrains increase within the particle, caus-ing a fracture to occur. Such fracturesthen create new cutting edges along thefracture plane. This process is repeatedwith each tungsten carbide particle,continuously renewing the cutting edgesuntil the entire content of tungsten car-bide particles is exhausted.

Tungsten carbide particles, with a hard-ness nearly that of diamonds, retain theirhardness at high temperatures and arenot affected by the heat generated fromthe cutting operation. The tough, resili-ent, nickel-silver alloy matrix securelyholds the tungsten carbide particles inplace and cushions the particles againstsevere impact.

Use of ItcoloyBowen Itcoloy is used to form the cut-ting or milling surfaces on milling shoes,rotary shoes, junk mills, section mills,milling stabilizers, piloted liner mills, orany tool that may be subjected to highabrasive wear and severe impact.

Tools dressed with Itcoloy are used tomill away all kinds of junk, including drillpipe, drill collars, bits, cones, casing,liners, and liner hangers. This advance-ment in metallurgy — which suspendsfragmented tungsten carbide particles ina resilient matrix — provides milling toolsrequiring minimum torque, that havehigh-speed cutting ability, and that haveincreased life or wearing ability.

Construction of Itcoloy RodBowen Itcoloy consists of selectedgrades of crushed sintered tungstencarbide particles imbedded in a resilientnickel-silver alloy matrix.

Itcoloy uses only the hardest steel cuttingsintered carbides. The sintered tungstencarbides are crushed, then sifted andgraded to appropriate screen mesh sizes.After screening, each particle is handselected to assure sharp, full bodiedparticles and to eliminate all slivers andsplinters that may have passed throughthe screen mesh.

After screening and grading, the crushedsintered tungsten carbide particles aremade into a rod form with a maximumconcentration of particles imbedded ina matrix of nickel-silver alloy that holdsthe particles in suspension. The matrixmaterial has an ultimate shear strengthof 100,000 psi.

Bowen Itcoloy is made in rod form sothat it may be applied in the field or anyshop wherever oxygen acetylene weldingequipment is available. For best appli-cation, described later in the text, Bowenrecommends the use of Bowen BrazingFlux and Bowen Tinning Rod.

Milling Shoesand Rotary ShoesBowen Milling Shoes or Bowen RotaryShoes are designed in various sizes andstyles to meet the various conditionsencountered in oil well fishing and wash-over operations. Illustrated herein aremany of the styles with an explanationof their intended service.

Overshot Milling Shoe is used to millaway jagged metal from the top of thefish so that the fish will pass easily intothe Overshot Bowl.

Packet Retriever Milling Shoe is usedto mill away the slips of a productionpacker without damage to the casingso that the remainder of the packer canbe retrieved.

Junk Basket Milling Shoe is used to millaway jagged edges from small junk or bitcones so that the junk will pass into thebasket and be retrieved, or for formationcutting to cut small cores.

Type A Rotary Shoe is used to cut metalon the fish without cutting the casing.Cuts on the inside diameter and thebottom. Does not cut on the outsidediameter.

Type B Rotary Shoe is used for washingover a fish and cutting metal or formationin the open hole. Cuts on the outsidediameter and the bottom. Does not cuton the inside diameter.

Type C Rotary Shoe is used for washingover and cutting metal, formation or ce-ment. Cuts freely on the inside diameter,the outside diameter, and the bottom.

Type D Rotary Shoe is used to cutmetal on the fish without cutting the cas-ing where clearances are limited. Cutson the inside diameter, and the bottom.Does not cut on the outside diameter.

A macro-photograph of a portion of an ItcoloyRod showing the concentration of tungstencarbide particles imbedded in the nickel-silveralloy matrix.

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Type E Rotary Shoe is used for washingover a fish and cutting metal, formationor cement in the open hole where clear-ances are limited. Cuts on the outsidediameter and the bottom. Does not cuton the inside diameter.

Type G Rotary Shoe is used for washingover and cutting metal, formation orcement in the open hole with limitedinside clearances. Cuts on the insidediameter, the outside diameter, and thebottom.

Type H Rotary Shoe is used for washingover and cutting metal in the open holewith limited clearance on the outsidediameter. Cuts on the inside diameter,the outside diameter, and the bottom.

Type I Rotary Shoe is used for washingover and cutting formation only. Saw-tooth design permits maximum circula-tion. Cuts on the bottom only. Does notcut on the outside diameter or insidediameter.

Type J Rotary Shoe is used for washingover and cutting formation only. Saw-tooth design with side wings permitsmaximum circulation. Cuts on the bottomand on the outside diameter. Does notcut on the inside diameter.

Type K Rotary Shoe is used for washingover and cutting on the bottom face only.Does not cut on the outside diameter orthe inside diameter.

Type F Rotary Shoe is used to size anddress the top of a fish inside the casing.Makes a tapered cut on the inside dia-meter, and cuts on the bottom. Does notcut on the outside diameter.

Bowen Milling Shoes and Bowen RotaryShoes hardfaced with Bowen Itcoloy arerecommended for all types of washoveroperations. The increased speed of cut-ting and penetration makes an Itcoloyhardfaced shoe more economical to usethan a conventional hard metal shoe.

Bowen Milling Shoes are used to millover and free stuck packers, spears,stabilizers, string reamers, rock bits orany metal objects which cannot beremoved from the well bore with conven-tional fishing procedures and fishingtools.

Bowen Rotary Shoes are excellent forwashing over stuck pipe to cut awayshales, clay, sand, salt, limestone,cement, anhydrite, red beds and otherformations.

Graded particle size of Bowen Itcoloyhardfacing for Milling Shoes and RotaryShoes is determined by the dimensionallimitations of the shoe itself, the dimen-sional limitations of the fish and the wellbore, and, finally, the work to be done.

Generally speaking, coarse grades(3/8" to 3/16") of Itcoloy are utilized formetal cutting, and medium grades (3/16"to 1/16") are utilized for formation andcement cutting. The fine grades (10–18mesh), or smaller, are used to preventabrasive wear on such items as tooljoints, stabilizer subs, etc.

Operation of Milling Shoesand Rotary ShoesMilling Shoes and Rotary Shoes are usedprimarily to dress a stuck fish so that agrappling or retrieving tool may engagethe fish.

In operation, the penetration rate isaffected by the hole condition, the rotaryspeed, the weight of the drill string uponthe milling shoe, the weight and viscosityof the drilling fluid, the dimensional sizeof the milling shoe, and finally, the sizeand hardness of the material to be milled.It is apparent from all of these variablesthat a concise applied weight and revo-lutions per minute cannot be stated toobtain the most efficient penetration rateexpressed in feet per hour.

Therefore, the optimum weight and rotaryspeed must be determined under actualoperating conditions. Revolutions perminute (rpm) may vary from 60 rpm to175 rpm. Washover or milling operationsshould begin with moderate speed andlow weight. Increase both weight andspeed until the desired, or optimum,penetration rate is attained.

OvershotMilling Shoe

Packer RetrieverMilling Shoe

Junk BasketMilling Shoe

Type ARotary Shoe

Type BRotary Shoe

Type CRotary Shoe

Type DRotary Shoe

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Lower the washover string into the welluntil the milling shoe is a few feet abovethe top of the fish. Start the pumps andcirculate the hole until the top of the fishis clean. Either conventional or reversecirculation may be used. Reverse circu-lation is often recommended becausethe velocity of the returns is greater.

Normal pump pressures are recom-mended with the mud weight andviscosity being sufficient to circulate thecuttings out of the hole. If metal cuttingsin great volume are anticipated, whichis not usually the case in washover oper-ations, consideration should be givento removing the metal cuttings from themud stream to prevent damage to thepumping equipment.

The volume and characteristics of thereturned cuttings should be checkedfrequently since they will provide a greatdeal of information on the washoverprogress. Metal cuttings being returnedwill vary in shape and size due to theItcoloy particle size being used andthe material being milled. Chip size isprimarily a function of the quality of thesteel being milled.

In the event that the penetration ratedeclines, it is advisable to change theweight or the rotary speed and, in somecases, to spud lightly to re-establish thedesired rate of progress.

Milling ToolsMilling tools are designed to mill awaya stuck fish that cannot be retrieved byconventional fishing methods.

Since milling is usually a follow-upoperation (after several fishing attempts),the fish to be milled away should befamiliar to the operator and therefore theselection of the milling tools should berelatively easy to determine, since thedimensional restrictions of the well boreor casing, and the work to be accom-plished are known.

The Milling Tool selected should providemaximum exposure of the milling edgeto the material to be milled, maximumreplacement of the milling edge as wearoccurs, and maximum circulation toremove the cuttings. Examples of MillingTools are described below.

NOTE: Conditions that might make an Itco-loy hardfaced pilot undesirable are whenthe inside of the pipe to be milled is badlydamaged, collapsed or contains junk. AnItcoloy hardfaced pilot is not recommendedbecause of the danger of the pilot “side-tracking” through the damaged pipe. Inthese cases, it is recommended that a TaperMill be run to restore the inside diameterof the pipe so that the pilot is free to alignthe pipe.

Operation of Milling ToolsBowen Milling Tools are simple tooperate. For best results, relatively fastrotary speeds should be available aswell as drill collars and drill pipe.

Junk Mills are used to mill away metalobjects in the hole that cannot beretrieved with grappling tools or junkbaskets.

The blade forms of all Junk Mills aredesigned so that they hold the junk to bemilled under the milling face. The millthus cuts continually rather than sweep-ing the junk ahead of the blades.

The Junk Mills selected should be 1/8to 1/4 inch less than the minimum insidediameter of the casing or open holethrough which it is to run.

Round Nose Mills are used primarilyto mill out the bottom of liners or casingwhich have been set with a bull plugduring original completion. Round NoseMills cut on the leading edge or nose,along the taper but not the full circumfer-ence or periphery of the mill.

Taper Mills are used primarily to mill outcollapsed pipe, to restore elliptical pipeto full bore, and to remove restrictionsfrom the inside diameter such as landingseats, bushings, and any other metalobjects that might restrict the well bore.Taper Mills have cutting faces along thetaper.

Type ERotary Shoe

Type FRotary Shoe

Type GRotary Shoe

Type HRotary Shoe

Type IRotary Shoe

Type JRotary Shoe

Type KRotary Shoe

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For maximum results, the mill shouldbe run on the bottom of a string of drillcollars weighing any where from 10,000to 15,000 pounds, depending uponthe size (OD) of the mill. Actual weightapplied to the mill will necessarily varydue to the size and type of mill, holecondition and depth, and the materialto be milled.

The volume and characteristics of thecuttings should be checked frequentlysince they will provide a great deal ofinformation about the milling progress.The metal cuttings being returned willvary in size and shape due to the Itcoloyparticle size and, more importantly,the material being milled. Chip size isprimarily a function of the quality of thesteel being milled.

High volume pumps will give the bestresults since high circulation rates willboth flush and cool the milling surfacesand circulate the metal cuttings to thesurface. The mud weight and viscosityshould be adequate to lift the metalcuttings to the surface. A mud viscosityof 50 to 80 centipoises will carry mostcuttings to the surface. Considerationshould be given to removing the metalcuttings from the mud stream to avoidany damage to the pumping equipment.

With consideration having been givento all of the above, lower the drillingstring to within a few feet of the object tobe milled. Start the pumps and circulatefreely to remove any sand or cuttingsbefore starting to mill.

Rotate with a moderate speed and slow-ly lower the drill string until the mill makescontact with the object to be milled.Increase rotation and gradually increaseweight until the desired or optimumpenetration rate is obtained. Suggestedspeeds are as follows:

Junk Mill Junk Millwith Regular Pin Connection

and Fishing Neck

Round Nose Mill Round Nose Millwith Regular Pin Connection

and Fishing Neck

Taper Mill Taper Millwith Regular Pin Connection

and Fishing Neck

OD of Mill Speed in RPM3-7/8 to 4-1/4 175

4-3/8 to 4-7/8 150

5 to 5-7/8 1256 to 6-7/8 100

7 to 7-7/8 90

8 to 8-7/8 809 to 9-7/8 75

10 to 10-7/8 70

11 to 11-7/8 6512 to 12-7/8 60

For ideal penetration rates, it will gener-ally be necessary to try different rotaryspeeds, weights and pump pressures.Whenever the penetration rate declines,it may be necessary to vary any one orall of these factors to re-establish an effi-cient penetration rate. Occasional spud-ding may also help.

Whenever the penetration rate cannotbe re-established by varying the factorsabove or by light spudding, removethe mill from the well, as the Itcoloy hard-facing has probably been worn away.

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Maintenance of Milling ToolsAll Bowen Milling Tools are of uncompli-cated construction and are thereforeeconomical to maintain. They should becleaned thoroughly after each run, withparticular attention to the threads. If thetool is to be stored for a period of time,either paint the surfaces or apply a rustinhibitor. The threads should be coatedwith a zinc base lubricant.

If the Itcoloy hardfacing has been wornaway or is under gauge, it should be builtup or restored to full gauge with Itcoloy.This service is available at the BowenHouston Plant, or it may be applied bya qualified welder wherever oxygen ace-tylene equipment is available by follow-ing the Application procedure.

Application of ItcoloyTo New ToolsItcoloy tungsten carbide hardfacing isrelatively easy to apply. Any qualifiedwelder familiar with brazing techniquescan successfully apply Itcoloy byobserving the following procedures andprecautions.

Oxygen acetylene equipment is usedthroughout the various stages of theprocedure, generally with a low pressureor soft flame. It is best to use a largertip than is used for welding mild steel.Adjust the torch for a low pressure neu-tral flame. (A neutral flame is composedof equal parts of oxygen and acetylene.)Heat is localized by working with theblue inner cone close to, but not actuallytouching, the surface to be hardfaced.

Keep the cone of the flame away fromthe tungsten carbide particles as muchas possible and avoid overheating theworking surface. It is important not tooverheat.

Arrange the working area so that the itemto be hardfaced is positioned for down-hand welding and secure the item in asuitable turning jig, if possible.

PRECAUTION: Make certain that the work-ing area is well ventilated so that the gasesgenerated during the procedure are carriedoff and away from the welder. The gasesgenerated are toxic and prolonged inhal-ation may produce nausea and sickness.

1. Thoroughly clean and brighten thebase metal to be hardfaced.

2. Secure the item or tool to be hard-faced in a suitable turning jig andposition it for downhand welding.Clamp a carbon mold block in posi-tion to define the hardface depositsection or weld a steel rod to thework piece of the diameter or exten-sion required.

For example, if the job is to build a rotarywashover shoe with four equally spacedtungsten carbide cutting surfaces 3/16" thick,leaving four equidistant fluid circulationcourses, then cut eight equal length 3/16"steel rods and weld these rods to the bodyto confine and define the tungsten carbidehardfacing. When-ever the required tungstencarbide build-up is relatively small, the car-bon mold block or the procedure describedabove need not be used, as the buildup canbe controlled entirely by manipulation of theparticles.

3. Preheat the entire area to be hard-faced as well as the adjacent areas.On small pieces, use the torch heat(neutral flame), playing the flameback and forth over the working areaand rotating the piece. Preheattemperatures will vary some what,depending upon the thickness of themetal to be hardfaced. On thin sec-tions the temperature will be 700° to750°F, while on thicker sections thetemperature required will be 900° ormore. In brief, the thicker the section,the higher the temperature. Visually,the base metal will be a dull cherryred.

Applying the Bowen Tinning Rod to the JunkMill. Note that the shaped carbon block is nowin position against the Junk Mill.

Preheating Junk Mill preparatory to applyingItcoloy. Note carbon block mold shaped toblade form in the lower left corner.

Applying Bowen Itcoloy to the Junk Mill.The shaped carbon block mold conforms theItcoloy to the desired shape and buildup.

The Junk Mill has been removed from the fix-ture and is positioned for finishing the bottomface of the mill with Itcoloy. Note that all ofthe cutting faces conform to the shape of thecarbon block mold.

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On larger pieces, it is advisable to havea gas jet directed upon the work piece.This has the advantage of assisting inthe preheating procedure and maintain-ing the work piece at a high temperature,therefore saving the welder considerabletime and reducing the amount of oxygenand acetylene consumed.

4. When the work piece is preheated tothe proper temperature, apply BowenBrazing Flux. Use a spoon or spatulato dust or sprinkle the Bowen BrazingFlux over the entire surface to behardfaced. The Bowen Brazing Fluxwill bubble and boil if the work pieceis properly preheated. Any oxides thatmay be present on the surface of thebase metal or that may be formedduring the welding operation will beremoved by the Bowen Brazing Fluxin the form of fusible slag. Continuepreheating until the Flux is clear andfluid.

5. Pick up a Bowen Tinning Rod and,using a soft neutral flame, add the tipof the rod to the puddle of the flux.As the rod melts, the draw of the heatwill cause the alloy to flow and followthe heat. Keep the torch in motion.The rate of the travel with the torchshould be just as fast as the rod willbond, making sure that the flux iskept on the surfaces. By continuallyplaying the heat of the torch into thebase metal, the tinning process willbe accomplished quickly and smooth-ly. When completed, the tinning alloywill measure about 1/16" thick.

NOTE: If the preheat temperature is notsufficient, the molten alloy will not flowsmoothly but will form in small balls on thebase metal.

Bowen Tinning Rod is a specially com-pounded nickel-silver brazing alloyparticularly suited as a base for BowenItcoloy. Bowen Tinning Rod has a work-ing temperature of 1,400° – 1,600° F andproduces a corrosion-resistant weld de-posit with a hardness of 160-170 Brinell,with a tensile strength of 100,000 psi.

6. Pick up a Bowen Itcoloy Rod andsupply to the desired thickness overthe tinned surface, keeping the softneutral flame moving evenly andsmoothly over the entire surface.Since Bowen Itcoly is available ina number of graded fragment thick-nesses, the desired buildup can usu-ally be made in one pass by usingthe correct particle size.

For example, if a thickness of 1/4" isdesired, use a Bowen Itcoloy Rod con-taining 1/4" graded tungsten carbideparticles.

While the matrix is still molten, the tung-sten carbide particles may be posi-tioned. Use a carbon rod to manipulatethe particles into the molten matrix —packing, overlapping, and positioningbefore the matrix solidifies. Propermanipulation during the application willreduce the need for grinding and shap-ing to size.

If a carbon rod is not available for mani-pulating the particles, then a tinning rodmay be used.

NOTE: Avoid directing the cone of the flameupon the tungsten carbide particles andavoid overheating. Overheating and burningthe tungsten carbide particles will resultin embrittlement of the particles or thedissolution of some particles, causing themto lose their cutting ability.

7. Upon completion of the hardfacingprocedure, set the work piece asideaway from drafts to cool slowly.Do not quench! It is recommendedthat the workpiece be covered withan asbestos blanket or wrapped in

aluminum foil to retard the coolingprocess. This will result in a tool withbetter cutting ability, or high abrasivequality with high impact strength.

8. After the tool has cooled to roomtemperature, it may be ground to thecorrect size and shape. Use a coarsegrit grinder and rough grind thehardfaced area to the correct I.D.,O.D., and shape for the serviceintended.

9. Clean off the tool, removing all weldspatter, slag, etc., especially notingthat the threads are clean. If the toolis to be stored for any length of timebefore use, either paint the tool orapply a good rust inhibitor.

To Rework ToolsMilling tools, junk mills, rotary shoes,and milling shoes that have been used inhard service in the field can be restoredto their original size and usefulnessby redressing them with Bowen Itcoloytungsten carbide hardfacing. It is impor-tant to redress such tools to their originalsize and shape since there is a definiterelationship between the tool’s size andshape and its intended service.

1. Clean the complete tool thoroughly.Pay particular attention to the threadson the tool because the heat gener-ated during redressing will causemud to cake and harden in thethreads.

2. Using a coarse grinder, rough grindand remove any burrs or irregularitiesdeveloped from previous use.

3. Examine the tool thoroughly todetermine if the base metal or steelsupport backing has been worn awayin previous use. If it has, build upthe base metal or steel support withAWS-ASTM E-6010 electrode or equi-valent to the diameter orextensionrequired.

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NOTE: The base metal or steel blade back-ing must support the Itcoloy hardfacingto within the fragment size being used.For example, if 1/8" fragment size tungstencarbide hardfacing is to be used, the steelsupport must be to 1/8" of the finishedextension.

4. Apply the Bowen Itcoloy tungstencarbide hardfacing in accordancewith the procedure as outlined in thepreceding pages.

Itcoloy ApplicationRefer to the unretouched photographsof samples above.

(a) Correct Application —This sampleshows the correct application atproper heat. The matrix is well bond-ed to the base metal. The tungstencarbide particles are compactlyspaced and securely imbedded inthe matrix material. The resultingapplication, when cool, has a slightlygolden hue.

(b) Improper Application — This sam-ple shows the result of too muchheat. The heat has dissolved thematrix material. The tungsten carbideparticles are burned and charred.The resulting application, when cool,has a black and burned appearance.

(c) Improper Application — Thissample shows the result of too littleheat. The matrix is not bonded to thebase metal. Although the tungstencarbide particles are imbedded inthe matrix, the material will chip andbreak away from the base metalwhen milling. The resulting applica-tion has a dull silver appearance.

Figure a Figure b Figure c Figure d

Unretouched Photographs of Itcoloy Application

(d) Improper Application — Thissample shows the result of impropermanipulation and spacing of thetungsten carbide particles. Althoughapplied with proper heat and wellbonded, large vacancies exist andthe result would be an inefficient mill-ing surface. In appearance, theresulting application would have theslightly golden hue as sample (a),but the vacancies or cavities wouldbe very apparent.

Bowen Itcoloy, Tinning Rod, and Brazing FluxBowen Itcoloy contains the maximum desired concentration of fragmented sinteredTungsten carbides interspersed in a tough resilient matrix. The carbide used are allsteel cutting grades with a hardness of 91 to 93 Rockwell “A”. The matrix is a specialnickel-silver alloy with a tensile strength of 100,000 psi. Bowen Itcoloy is packed in car-tons of approximately ten pounds each and is available in the following graded sizes:

Nominal Size Graded Particle Size Rod Size Approximate Weight Per Rod

3/8 3/8" to 1 /4" 3/8" x 3/8" x 18" 14-7/8 oz.5/16 5/16" to 1/ 4" 5/16" x 5/16" x 18" 12 oz.

3/16 3/16" to 1/8" 1 /4" x 3/16" x 18" 10-5/8 oz.

1/8 1/8" to 1/16" 1/ 4" x 3/16" x 18" 9-1/2 oz.10 – 18 10 to 18 Screen Mesh 1/ 4" x 3/16" x 18" 7-1/4 oz.

18 – 30 18 to 30 Screen Mesh 3/16" x 3/16" x 18" 5-1/2 oz.

30 – 45 30 to 45 Screen Mesh 3/16" x 3/16" x 18" 5-1/4 oz.

Bowen Itcoloy Bowen Brazing FluxBowen Tinning Rod

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Bowen Rotary Shoe BlanksNo. of Standard Minimum Weight

Teeth Connection OD of Body ID of Body Length lbs

6 4" F.J. 4" 3-1/4" 16" 186 4-1/2" API Casing 5-1/8" 3-3/4" 16" 42

6 4-1/2" F.J. 4-1/2" 3-3/4" 16" 20

6 4-1/2" E.U. or E.L. 4-7/8" 3-3/4" 16" 326 4-3/4" API Casing 5-1/2" 4-1/16" 16" 45

6 4-3/4" F.J. 4-3/4" 4-1/16" 16" 28

6 4-3/4" E.U. or E.L. 5-1/8" 4-1/16" 16" 346 5" API Casing 5-7/8" 4-3/16" 16" 47

6 5" F.J. 5" 4-3/16" 16" 23

6 5" E.U. or E.L. 5-3/8" 4-3/16" 16" 396 5-1/2" API Casing 6-3/8" 4-5/8" 16" 50

6 5-1/2" F.J. 5-1/2" 4-5/8" 16" 30

6 5-1/2" E.U. or E.L. 5-7/8" 4-9/16" 16" 476 5-3/4“ API Casing 6-5/8” 5" 16" 52

6 5-3/4" F.J. 5-3/4" 5" 16" 26

6 5-3/4" E.U. or E.L. 6-1/8" 5" 16" 306 6" API Casing 6-3/4" 5-3/16" 16" 53

6 6" F.J. 6" 5-3/16" 16" 28

6 6" E.U. or E.L. 6-3/8" 5-3/16" 16" 486 6-5/8" API Casing 7-1/2" 5-11/16" 16" 70

6 6-5/8" F.J. 6-5/8" 5-11/16" 16" 41

6 6-5/8" E.U. or E.L. 7" 5-5/8" 16" 656 7" API Casing 7-7/8" 5-13/16" 16" 75

6 7" F.J. 7" 5-13/16" 16" 47

6 7" E.U. or E.L. 7-1/2" 5-13/16" 16" 72

8 7-5/8" API Casing 8-5/8" 6-5/8" 16" 858 7-5/8" F.J. 7-5/8" 6-5/8" 16" 47

8 7-5/8" E.U. or E.L. 8-1/16" 6-9/16" 16" 76

8 8-1/8" API Casing 9-1/8" 7-1/8" 16" 928 8-1/8" F.J. 8-1/8" 7-1/8" 16" 50

8 8-5/8" API Casing 9-3/4" 7-1/2" 16" 100

8 8-5/8" F.J. 8-5/8" 7-1/2" 16" 608 8-5/8" E.U. or E.L. 9-1/8" 7-7/16" 16" 97

10 9" API Casing 10-1/8" 7-13/16" 16" 120

10 9" F.J. 9" 7-13/16" 16" 5610 9" E.U. or E.L. 9-1/2" 7-3/4" 16" 78

10 9-5/8" API Casing 10-3/4" 8-1/2" 16" 128

10 9-5/8" F.J. 9-5/8" 8-1/2" 16" 6810 9-5/8" E.U. or E.L. 10-1/8" 8-7/16" 16" 118

10 10-3/4" API Casing 12" 9-3/4" 16" 140

10 10-3/4" F.J. 10-3/4" 9-3/4" 16" 6810 11-3/4" F.J. 11-3/4" 10-3/4" 16" 160

10 11-3/4" API Casing 12-7/8" 10-3/4" 16" 160

10 13-3/8" API Casing 14-1/2" 12-1/4" 16" 19010 16" API Casing 17" 15-1/4" 16" 190

Special Notes:1. Unless otherwise specified, Shoes will be furnished with same ID as washover string.2. Any specified ID larger than standard, can be furnished with no additional charge.3. All Rotary Shoes listed above are available also dressed with crushed tungsten carbide hardfacing.

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Bowen Milling ToolsMill Size (OD) 2-1/4 – 2-5/8 – 2-7/8 – 3-1/4 – 3-1/4 – 4-3/8 – 4-5/8 – 4-7/8 – 5-1/8 – 5-3/8 –

2-1/2 2-3/4 3-1/8 3-5/8 4-1/4 4-1/2 4-3/4 5 5-1/4 5-1/2Top Connection – Pin 1-13/16 1-1/4 1-1/4 2-3/8 2-3/8 2-7/8 2-7/8 2-7/8 3-1/2 3-1/2

Wilson A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. F.J. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg.

Catalog Standard ‡ ‡ ‡ ‡Junk Mill Part No. 41618 41621 41623 41626 41630 41635 41635 41635 41641 41641

Weight 5 6 7 8 9 15 16 17 20 21Round Nose Mill (60° Incl. Angle) Part No. 41918 41921 41923 41926 41930 41935 41935 41935 41941 41941

Weight 8 9 11 13 15 25 25 25 32 33Taper Mill (30° Incl. Angle) Part No. — — — — 41999 42000 42000 42000 42001 42001

Weight — — — — 16 33 33 33 42 4210" Fishing Neck for Above Mills Part No. — — — — 42027 42028 42028 42028 42029 42029Extra Charge Weight — — — — 16 28 28 28 35 35Fishing Neck OD – Inches — — — — 3-1/8 3-3/4 3-3/4 3-3/4 4-1/4 4-1/4

Mill Size (OD) 5-5/8 – 5-7/8 – 6-1/8 – 6-3/8 – 6-5/8 – 6-7/8 – 7-1/8 – 7-3/8 – 7-5/8 – 7-7/8 – 5-3/4 6 6-1/4 6-1/2 6-3/4 7 7-1/4 7-1/2 7-3/4 8

Top Connection – Pin 3-1/2 3-1/2 3-1/2 3-1/2 3-1/2 3-1/2 3-1/2 4-1/2 4-1/2 4-1/2 A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg.

Catalog Standard ‡ ‡ ‡Junk Mill Part No. 41641 41647 41647 41647 41653 41653 41653 41659 41659 41659

Weight 22 25 26 27 31 32 33 39 40 41Round Nose Mill (60° Incl. Angle) Part No. 41941 41947 41947 41947 41953 41953 41953 41959 41959 41959

Weight 34 39 38 39 49 50 51 79 80 81Tapper Mill (30° Incl. Angle) Part No. 42001 42002 42002 42002 42003 42003 42003 42004 42004 42004

Weight 42 52 52 53 65 65 65 108 110 11210" Fishing Neck for Above Mills Part No. 42029 42029 42029 42029 42029 42029 42029 42030 42030 42030Extra Charge Weight 35 35 35 35 35 35 35 62 62 62Fishing Neck OD – Inches 4-1/4 4-1/4 4-1/4 4-1/4 4-1/4 4-1/4 4-1/4 5-3/4 5-3/4 5-3/4

Mill Size (OD) 8-1/8 – 8-3/8 – 8-5/8 – 8-7/8 – 9-1/8 – 9-3/8 – 9-5/8 – 9-7/8 – 10-1/8 – 10-3/8 – 8-1/4 8-1/2 8-3/4 9 9-1/4 9-1/2 9-3/4 10 10-1/4 10-1/2

Top Connection – Pin 4-1/2 4-1/2 4-1/2 4-1/2 4-1/2 4-1/2 6-5/8 6-5/8 6-5/8 6-5/8 A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg.

Catalog Standard ‡ ‡ ‡ ‡ ‡Junk Mill Part No. 41665 41665 41665 41671 41671 41671 41677 41677 41677 41683

Weight 54 55 56 68 70 72 107 115 121 128Round Nose Mill (60° Incl. Angle) Part No. 41965 41965 41965 41971 41971 41971 41977 41977 41977 41983

Weight 84 85 86 118 120 122 175 181 187 218Taper Mill (30° Incl. Angle) Part No. 42005 42005 42005 42006 42006 42006 42007 42007 42007 42008

Weight 116 118 120 160 168 174 233 239 245 29010" Fishing Neck for Above Mills Part No. 42030 42030 42030 42030 42030 42030 42031 42031 42031 42031Extra Charge Weight 62 62 62 62 62 62 105 105 105 105Fishing Neck OD – Inches 5-3/4 5-3/4 5-3/4 5-3/4 5-3/4 5-3/4 7-3/4 7-3/4 7-3/4 7-3/4

Mill Size (OD) 10-5/8 – 10-7/8 – 11-1/8 – 11-3/8 – 11-5/8 – 11-7/8 – 12-1/8 – 12-1/2 – 14-1/8 – 17-3/8 – 10-3/4 11 11-1/4 11-1/2 11-3/4 12 12-1/4 14 17-1/4 Up

Top Connection – Pin 6-5/8 6-5/8 6-5/8 6-5/8 6-5/8 6-5/8 6-5/8 6-5/8 7-5/8 7-5/8 A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. A.P.I. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg. Reg.

Catalog Standard ‡ ‡ ‡Junk Mill Part No. 41683 41683 41689 41689 41695 41695 41695 41695 68807 152359

Weight 134 139 143 149 155 162 168 174 — —Round Nose Mill (60° Incl. Angle) Part No. 41983 41983 41989 41989 41989 41995 41995 41995 — —

Weight 220 226 229 235 241 280 284 288 — —Taper Mill (30° Incl. Angle) Part No. 42008 42008 42009 42009 42009 42010 42010 42010 152517 152518

Weight 296 302 298 304 310 370 376 382 — —10" Fishing Neck for Above Mills Part No. 42031 42031 42031 42031 42031 42031 42031 42031 — —Extra Charge Weight 105 105 105 105 105 105 105 105 — —Fishing Neck OD – Inches 7-3/4 7-3/4 7-3/4 7-3/4 7-3/4 7-3/4 7-3/4 7-3/4 — —

How to OrderSpecify:

(1) Name and part number of Mill(2) O.D. of Mill(3) Top connection, if other than standard(4) If Fishing Neck is desired, order Mill and Fishing Neck by number

Recommended for Redressing Mills:(1) Bowen Itcoloy(2) Bowen Tinning Rod(3) Bowen Brazing Flux

w w w . n o v . c o m© 2005 National Oilwell Varco

PDF/0905

MANUAL NO. 5100 R3

d o w n h o l e . t o o l s @ n o v . c o m

CorporateHeadquarters

10000 Richmond AvenueHouston, Texas 77042United StatesPhone: 713 346 7500Fax: 713 346 4493

Alaska4111 IngraAnchorage, Alaska 99503United StatesPhone: 907 563 5253Fax: 907 561 0071

California4117 Atlas CourtBakersfield, California 99308United StatesPhone: 661 395 0165Fax: 661 328 1827

Louisiana108 Nova DriveBroussard, Louisiana 70518United StatesPhone: 337 839 2400Fax: 337 839 2211

190 Thompson RoadHouma, Louisiana 70363United StatesPhone: 985 851 1111Fax: 985 851 1117

Mississippi2930 Industrial Blvd.Laurel, Mississippi 39440United StatesPhone: 601 649 8671Fax: 601 649 8673

New Mexico#14 CR 5860Farmington, New Mexico 87401United StatesPhone: 505 326 4303Fax: 505 326 4304

North Dakota3202 1st Avenue WestWilliston, North Dakota 58801United StatesPhone: 701 774 0091Fax: 701 774 0092

Oklahoma3800 Thomas RoadOklahoma City, Oklahoma 73179United StatesPhone: 405 677 2484Toll Free: 877 760 1711Fax: 405 677 2457

Texas1249 Commerce RoadAlice, Texas 78332United StatesPhone: 361 664 8013Fax: 361 664 0462

8411 Irvington Boulevard*Houston, Texas 77022United StatesPhone: 713 691 7800Fax: 713 691 7807

2810 Highway 135 NorthKilgore, Texas 75662United StatesPhone: 903 984 2553Fax: 903 984 7170

10720 West I-20 EastOdessa, Texas 79765United StatesPhone: 432 563 1173Fax: 432 563 1182

30444 Southwest FreewayRosenberg, Texas 77471United StatesPhone: 281 341 5365Fax: 281 344 1986

Utah1553 East Highway 40Vernal, Utah 84078United StatesPhone: 435 789 0670Fax: 435 789 6568

West VirginiaRoute 2, Murphy Run RoadClarksburg, West Virginia 26301United StatesPhone: 304 622 4303Fax: 304 623 2174

Wyoming1283 N. Derrick DriveUnit 1, Box 2Casper, Wyoming 82604United StatesPhone: 307 237 3100Fax: 307 237 2546

Canada9120 – 34A AvenueEdmonton, Alberta T6E 5P4CanadaPhone: 780 702 5209Fax: 780 463 2348

3550 93 Street*Edmonton, Alberta T6E 5N3CanadaPhone: 780 944 3929Fax: 780 430 0760

1100 540 5th Avenue SW (Mailing)1010 540 5th Avenue SW (Office)Calgary, Alberta T2P OM2CanadaPhone: 403 250 8000Fax: 403 294 5790

England2 Isbourne WayWinchcombeCheltenhamGlos, GL54 5NSEnglandPhone: 44 (0) 1242 603975Fax: 44(0) 1242 602614

DubaiNr. R/A 13, Daimler Chrysler StreetP.O. Box 61490Jebel Ali Free ZoneDubaiUAEPhone: 971 4 8838776Fax: 971 4 8838795

IndonesiaCilandak Commercial Estate Unit 105Jl. Raya Cilandak KKOP.O. Box 7541Jakarta, 12560IndonesiaPhone: 62 21 782 6088Fax: 62 21 782 6086

Scotland10 Kirkton AvenuePitmedden Road Industrial EstateDyce, Aberdeen AB21 0BFScotlandPhone: 441 224 334800Fax: 441 224 723034

Singapore9 Tuas Avenue 5Singapore, 639335SingaporePhone: 65 68611566Fax: 65 68610728

GermanyEdesser Straße 131234 Edemissen BerkhöpenPostfach 31232GermanyPhone: 49 5176 97670Fax: 49 5176 9767 22

* Denotes Manufacturing and Engineeringfacilities

Downhole Solutions

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Engineering and Project Management Solutions

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Production Solutions

Supply Chain Solutions

Tubular and Corrosion Control Solutions

Well Service and Completion Solutions