Abrasive technologies

BACHELOR OF ENGINEERINGBACHELOR OF ENGINEERING

MANUFACTURING TECHNOLOGIESMANUFACTURING TECHNOLOGIES

ABRASIVE TECHNOLOGIESABRASIVE TECHNOLOGIES

by Endika Gandarias

2by Endika Gandarias

Dr. ENDIKA GANDARIAS MINTEGI

Mechanical and Manufacturing department

Mondragon Unibertsitatea - www.mondragon.edu(Basque Country)

www.linkedin.com/in/endika-gandarias-mintegi-91174653

Further presentations: www.symbaloo.com/mix/manufacturingtechnology

http://www.mondragon.edu/eps

http://www.linkedin.com/in/endika-gandarias-mintegi-91174653

http://www.symbaloo.com/mix/manufacturingtechnology

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CONTENTS BIBLIOGRAPHY INTRODUCTION GRINDING BENCH GRINDING BENCH GRINDING BLASTING BLASTING WIRE BRUSHING WIRE BRUSHING GRINDING MASS FINISHING MASS FINISHING COATED ABRASIVE COATED ABRASIVE HONING HONING POLISHING AND BUFFING POLISHING AND BUFFING LAPPING LAPPING SUPERFINISHING SUPERFINISHING OTHERS:

ABRASIVE FLOW MACHINING ELECTRO-POLISHING ELECTROLYTIC GRINDING CHEMICAL MECHANICAL POLISHING POLISHING USING MAGNETIC FIELDS

GLOSSARYby Endika Gandarias

HIGH

LOW BETTER

WORSE

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BIBLIOGRAPHY

BIBLIOGRAPHY

by Endika Gandarias

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The author would like to thank all the bibliographic references and videos that

have contributed to the elaboration of these presentations.

For bibliographic references, please refer to:

• http://www.slideshare.net/endika55/bibliography-71763364 (PDF file)

• http://www.slideshare.net/endika55/bibliography-71763366 (PPT file)

For videos, please refer to:

• www.symbaloo.com/mix/manufacturingtechnology

BIBLIOGRAPHY

by Endika Gandarias

http://www.slideshare.net/endika55/bibliography-71763364






http://www.symbaloo.com/mix/manufacturingtechnology

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INTRODUCTION

INTRODUCTION

by Endika Gandarias

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INTRODUCTION

• Usually brought into play after machining, casting, forging, sheet metal forming, etc.

• It can be used on all type of materials.

• A variety of abrasive machining processes and machinery is available.

• Abrasive machining is necessary and economical when:

• Hard materials

• Brittle materials

• Excellent surface finish and dimensional tolerances are required.

by Endika Gandarias

Rz: Maximum height of the roughness profile

Ra: Arithmetical mean deviation of the roughness profile

Rq: Root mean square deviation of the roughness profile

Roughness 2D Parameters

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INTRODUCTION

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• All abrasive operations can be considered as material removal processes with geometrically undefined cutting edges. Each abrasive grain acts like a single cutting tool with undefined geometry but usually with high negative rake angle.

INTRODUCTION

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Sharping with stones

Rotary stonePedal with shank

and connecting rodCHARLES MOSELEY

Cylindrical grinding machineSWEN PULSON Extra-strong

grinding wheel

BROWN & SHARPE Universal grindingNORTON

Horizontal grinding tool holderACHESON

Carborundum (Silicon carbide)CINCINNATI Centerless

grinding machine GENERAL ELECTRICSynthetic diamond

INTRODUCTION

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INTRODUCTION

by Endika Gandarias

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GRINDING

by Endika Gandarias

GRINDING

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GRINDING

Introduction

It is an abrasive technology in which abrasive particles are contained in bonded grinding wheel.

The feed (F) and depth of cut (ap) in grinding are small, while the cutting speed (Vc) is high.

Dimensional accuracy: 0,3 – 0,5 µm Surface finish (Ra) ~ 0,1 – 1,6 µm Specific cutting energy: 50 J/mm3

by Endika Gandarias

VIDEO

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Introduction

GRINDING

A grinding wheel consists of: Hard abrasive grains called grits perform the cutting or material removal Hardness Bonding material holds particles in place and gives the profile to the wheel Toughness

Conventional abrasive wheel materials: • Aluminium oxide (Al2O3)• Silicon carbide wheels (SiC)

Superabrasive wheels:

• Diamond • CBN (Cubic Boron Nitride)

Conventional abrasive wheels Superabrasive wheels

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1 14192 250 X 25 X 25 51-A-36-L-5-V-23 40m/s

GEOMETRY DIMENSIONS COMPOSITION Max SPEEDPRODUCT NUMBER

Grinding wheel specification

It is needed to be specified:• Wheel diameter (D)• Width and depth of rim (T)• Bore diameter (H)

GRINDING

by Endika Gandarias

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Standard Marking System for Aluminum-Oxide and Silicon-Carbide Bonded Abrasives

GRINDING


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ABRASIVE TYPE: Al2O3 (2000-3000) high tensile strength materials, ductile materials “corundum” SiC (2100-3000) low tensile strength, brittle and non metallic materials

“carborundum” CBN (4000-5000) very hard materials “borazon” Diamond (7000-8000) carbide & very hard non ferrous materials

ABRASIVE GRAIN SIZE: Coarse Soft & ductile materials or poor Ra = roughing Fine Hard & brittle materials or excellent Ra = finishing

GRADE (abrasive grain-bonding joining strength): Soft wheel hard materials machining (to have fresh abrasive) or poor Ra = roughing Hard wheel soft materials machining or excellent Ra = finishing

STRUCTURE (porosity): Open Soft & ductile materials High removal rate or poor Ra = roughing Dense Long wheel life & precise wheel forms/profiles or excellent Ra = finishing

BOND TYPE: Vitrified: most common, brittle bond Resinoid: more flexible bond Rubber: very flexible bond

GRINDING


by Endika Gandarias

VIDEO

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GRINDING

by Endika Gandarias

The heavy point of the grinding wheel is marked with an arrow.Depending of the wheel manufacturer, it needs to be mounted with the arrow pointing downwards or upwards. VIDEO

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Truing is the process of making a grinding wheel round and concentric with the grinding wheel spindle axis. Truing is also the process of forming a specific shape on the face of the wheel.

Dressing is the process of conditioning the surface of a trued wheel to expose the grain for efficient grinding action.

GRINDING

Truing and dressing a grinding wheel

After truing

After dressing

Truing and dressing can often be performed at the same time, even using the same tool. WHEEL OR GRINDING

DRESSERS

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VIDEO

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GRINDING

• It is used to remove material from flat surfaces.

• Spindle position can be horizontal or vertical.

• Dimensional tolerance ~ IT5 – IT6 • Surface finish (Ra) ~ 0,15 – 0,6 µm

Grinding technology classification

Flat or surface grinding

by Endika Gandarias

VIDEO

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ALTERNATIVEWORKTABLE

ALTERNATIVEWORKTABLE

ROTATIVEWORKTABLE

ROTATIVEWORKTABLE

• Long and narrow surfaces.

• Worse efficiency than the frontal grinding.

• Better finishing than the frontal grinding.

• High material start-up rate.

• Worse finishing than the tangential grinding.

• Tools: rings, cups, segments

GRINDING


TANGENTIAL GRINDING WHEEL FRONTAL GRINDING WHEEL

VIDEO VIDEO


by Endika Gandarias

VIDEO

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Props Guide

Engine Cutting blade

GRINDING


APPLICATIONS

Gear

Other


by Endika Gandarias

TANGENTIAL

FRONTAL FRONTAL

TANGENTIAL TANGENTIAL

VIDEO

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GRINDING

Creep feed grinding

It uses large depth of cuts (typically ap on the order of 1 - 6 mm) and low feed rates (F).

The wheel is often continuously dressed. It is essential to use a high pressure coolant system and soft wheels with open

structure to keep temperature low. Advantages: High material removal rates and productivity (the wheel is

continuously cutting).


Conventional grinding contrasted to creep feed grinding

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GRINDING

Creep feed grinding


APPLICATIONS

Gas turbine bladeGear Other parts

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Cylindrical grinding

GRINDING


• It is used to remove external or internal cylindrical surfaces.

• It is also known as Universal grinding.

• The workpiece is usually held in a rotating chuck in the headstock or between centers. • The wheel rotates at very high rotational speed (N).


by Endika Gandarias

Feed

VIDEO

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GRINDING


EXTERNAL GRINDING OPERATIONS

(a)Traverse grinding (single axis feed movement)

(b) Plunge grinding (penetration movement)

(c) Profile grinding (multiple axes simultaneous feed movement)

VIDEO

by Endika Gandarias

VIDEO

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GRINDING


INTERNAL GRINDING OPERATIONS

VIDEO

(a) Traverse grinding

(b) Plunge grinding (c) Profile grinding

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GRINDING


SPECIAL OPERATIONS

STEPPED SHAPE GRINDING WHEEL THREAD GRINDING

(a) traverse grinding (b) plunge grinding

by Endika Gandarias

VIDEOGEAR GRINDING

VIDEO

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GRINDING


SPECIAL OPERATIONS

The part rotation and the distance x between centers is varied and synchronized to grind the particular workpiece shape.

GRINDING A NON-CYLINDRICAL PART

VIDEOby Endika Gandarias

VIDEO

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GRINDING


APPLICATIONS

Transmission shaft

Internal axis gear Aerospace rotor

Axle Spindle housing

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VIDEO

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GRINDING


APPLICATIONS

Internal thread grinding Worm grinding

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Centerless grinding

GRINDING


• It is used for high length to diameter ratio parts.• Workpiece is NOT supported by centers or chucks,

but by a blade or between rollers.• Easy to be automatizated.


(a) Through-feed grinding (b) Plunge grinding

EXTERNAL GRINDING OPERATIONS

VIDEOVIDEO

by Endika Gandarias

(a) Through-feed grinding

VIDEO

VIDEO

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Centerless grinding

GRINDING


(c) Internal centerless grinding

INTERNAL GRINDING OPERATIONS

by Endika Gandarias

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GRINDING


APPLICATIONS

Bars / tubes

Gearbox shaftCamshaft tube

Centerless grinding

Piston

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BENCH GRINDING

by Endika Gandarias

BENCH GRINDING

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The work is held (usually manually) against the flat surface of the wheel to accomplish the grinding operation.

It can be a bench grinder or pedestal grinder.

Surface finish (Ra) ~ 0,2 - 1,6 µm

BENCH GRINDING

by Endika Gandarias

VIDEO

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BLASTING

by Endika Gandarias

BLASTING

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This is the finishing method by spraying blasting abrasives from a nozzle with the force of compressed air to workpieces.

It is used for: Cleaning Deburring Descaling Finishing Peening (increases hardness and eliminates residual stresses)

Surface finish (Ra) ~ 1,5 µm

BLASTING

by Endika Gandarias

VIDEOVIDEO

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WIRE BRUSHING

by Endika Gandarias

WIRE BRUSHING

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WIRE BRUSHING

It produces a fine and controlled surface texture.

Wire brushing is typically used for: removal of rust or corrosion from metal objects. rough-polishing castings, hot-rolled steel,…

Brushes can be made of nylon, steel or brass filaments, and may contain abrasives.

Surface finish (Ra) ~ 0,1 – 1,5 µm

by Endika Gandarias

VIDEOVIDEO

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MASS FINISHING

by Endika Gandarias

MASS FINISHING

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MASS FINISHING

Mass finishing is a surface improving mass-production system. A mixture of parts, abrasive media (vitrified, alumina, plastic, organic or metallic) and compounds (liquid or powder) are placed into a container or barrel, and rotated at a predetermined speed.

It is used for: Deburring Radiusing Smoothing Descaling Luster and mirror finishing.

There are several types of barrel motion:

Centrifugal barrel Centrifugal disc Vibratory bowl Rotary tumbling

Surface finish (Ra) ~ 0,05 – 1,6 µm

HIGH

LOW

Centrifugal barrel Centrifugal disc

Vibratory bowl Barrel / Rotary tumbling

by Endika Gandarias

VIDEO

VIDEO VIDEO

VIDEO VIDEO

VIDEO

VIDEO

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COATED ABRASIVE

by Endika Gandarias

COATED ABRASIVE

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COATED ABRASIVE

Sandpaper and emery cloth are common examples of coated abrasives. They are available in multiple geometries: sheets, belts, disks,… The precision of the surface finish depends primarily on the grain size. Abrasive grains (mostly Al2O3, ZrO2, SiC) are uniformly distributed on flexible backing

material (paper, cotton, rayon polyester) with the tips upward. Matrix or make coat is made of resins.

by Endika Gandarias

VIDEO

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COATED ABRASIVE

by Endika Gandarias

FEPA P GRAIN DIAMETER (µm)

VERY COARSE

P12 1815

P16 1324

P20 1000

P24 764

COARSE

P30 642

P36 538

P40 425

P50 336

MEDIUM

P60 269

P80 201

P100 162

FINE

P120 125

P150 100

P180 82

P220 68

FEPA P GRAIN DIAMETER (µm)

VERY FINE

P240 58.5

P280 52.2

P320 46.2

EXTRA FINE

P360 40.5

P400 35.0

P500 30.2

P600 25.8

P800 21.8

SUPER FINE

P1000 18.3

P1200 15.3

P1500 12.6

P2000 10.3

P2500 8.4

P3000 7

P5000 5

Obtained surface roughness (Ra) depends on the workpiece material.

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Coated abrasives are also used as belts for high material removal rate and good surface finish.

Typical applications: surgical implants, medical & dental instruments, golf clubs, firearms, turbine blades.

Dimensional tolerance ~ IT10 – IT11 Surface finish ~ 0,4 – 0,8 µm

COATED ABRASIVE

Belt grinding

by Endika Gandarias

VIDEOVIDEO

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HONING

by Endika Gandarias

HONING

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HONING

Honing is used to improve the surface finish and roundness of bored or ground holes. It creates a characteristic cross-hatched surface that retains lubrication. As it is a slow rotation operation, no heat affected zone (HAZ) appears. Typical application: bores of internal combustion engines.

Dimensional tolerance ~ IT4 – IT5 Surface finish (Ra) ~ 0,05 – 0,2 µm (Al2O3 or SiC)

by Endika Gandarias

Osc

illat

ion

Va

Slow rotation Vu

VIDEOVIDEO

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HONING

by Endika Gandarias

(Va)(Vu)

VIDEO

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POLISHING AND BUFFING

by Endika Gandarias


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Abrasive particles are glued to the outside periphery of the polishing wheel and it rotates at high speeds.

Polishing is used to remove scratches and burrs.

Polishing operations are often accomplished manually.

The polishing wheel is made of fabrics, leather or felt.

Surface finish (Ra) ~ 0.02 – 0.4 μm

BEFOREAFTER

Polishing

by Endika Gandarias

VIDEOVIDEO

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It is very similar to polishing, in which abrasive particles are not glued to the wheel but are loose. Buffing is a finer operation than polishing.

Ideal for enhancing and brightening existing finishes, taking out stains in metals and bringing out a new lustre in work surfaces.

Polishing operations are often accomplished manually.

The buffing wheel is made of linen, cotton, bleached muslin, flannel, or other soft cloth materials.


Buffing


by Endika Gandarias

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LAPPING

by Endika Gandarias

LAPPING

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LAPPING

(b) lapping on cylindrical surfaces(a) lapping on flat surfaces

It is a low speed, low ablading process.

Lapping uses fluid suspension of very small abrasive particles between workpiece and lap. Lap usually made of cast iron, copper, leather, or cloth.

Typical application: optical lenses, metallic bearing surfaces, gages.

Dimensional tolerance ~ IT4 – IT5 Surface finish (Ra) ~ 0.025 – 0.1 μm

by Endika Gandarias

VIDEO VIDEO

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SUPERFINISHING

by Endika Gandarias

SUPERFINISHING

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SUPERFINISHING

It is similar to honing (also called “microhoning”): Shorter strokes (<5 mm) Higher frequencies (>400 cycles/min) Lower pressures (10-40 psi) Smaller grit size

Copious amount of low viscosity lubricant-coolant is used and it establishes a continuous film between the stone and the workpiece and separates them.

Stroke paths controlled so that a single grit never traverses the same path twice.

Dimensional tolerance ~ IT3 – IT4 Surface finish (Ra) ~ 0.01 – 0.04 μm

(a) cylindrical microhoning (b) centerless microhoning

by Endika Gandarias

VIDEOVIDEO

VIDEO

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OTHERS

by Endika Gandarias

OTHERS

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OTHERS

A putty of abrasive grains (SiC or diamond) is forced back and forth through the workpiece.

It is particularly suitabe for workpieces with internal cavities.

It is used for: Deburring Radiusing Polishing

Dimensional tolerance ~ ± 0,005mm Surface finish (Ra) ~ 0,05 – 0,4 µm

Abrasive Flow Machining

by Endika Gandarias

VIDEO

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This polishing method melts the surface of a workpiece by applying an electrolytic solution and an electric DC current to workpiece.

Mirrorlike finishes can be obtained on metal surfaces. It is very suitable for irregular geometries.

This process is also used for deburring operations.

Typical application: medical instrumentation, bone screws, stainless steel surfaces.


OTHERS

Electropolishing

by Endika Gandarias

VIDEOVIDEO

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It is a variant of ElectroChemical Machining (ECM), and it is also known as electrochemical grinding.

It is a process that combines electrochemical energy with mechanical energy to remove material by grinding with a negatively charged abrasive grinding wheel, an electrolyte fluid, and a positively charged workpiece.

Typically 90% of the metal is removed by electrolysis and 10% from the abrasive grinding wheel (the wheel lasts a longer time). Thus, difficult materials independent of their hardness or strength can be machined.

The wheel and workpiece must be electrically conductive.

OTHERS

Electrolytic grinding (ECG)

by Endika Gandarias

VIDEO

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OTHERS

Chemical Mechanical Polishing/Planarization is a process of smoothing surfaces.

It is a combination of mechanical free abrasive polishing and chemical etching (increases material removal rate).

It may contain 1 or more workpiece carriers.

Typical applications: silicon wafers and integrated circuits.


Chemical Mechanical Polishing (CMP)

by Endika Gandarias

VIDEOVIDEO

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OTHERS

A magnetic field is used to force a homogeneous mixture of magnetic particles and abrasive particles against the target surface.

The particles can be introduced into areas which are hard to reach by conventional techniques.

Typical applications: medical components, fluid systems, optics, dies and molds, electronic components, microelectromechanical systems, and mechanical components.

Surface finish (Ra) ~ 200 – 0.001 μm

(a) magnetic float polishing of ceramice balls (b) magnetic field assisted polishing of rollers

Polishing Using Magnetic Fields

by Endika Gandarias

VIDEOVIDEO

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GLOSSARY

GLOSSARY

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GLOSSARY

by Endika Gandarias

ENGLISH SPANISH BASQUE

Ablading Abrasión UrratzeAbrasive Abrasivo UrratzaileAccuracy Precisión DoitasunAttrition Erosión ErosioAxial cutting depth Profundidad de pasada axial Sakontze sakoneraAxle Eje ArdatzBacking Sustrato / Apoyo SubstratuBarrel Barril / Tonel Upel / BarrikaBarrel finishing Tambor de pulido Leunketa danborBatch Lote SortaBearing Rodamiento ErrodamenduBed Base OinarriBelt Cinta / Banda BandaBelt grinding Lijado con cinta/banda Banda bidezko lixatzeBench grinding Esmerilado EsmerilaketaBetween centers Entre centros Zentru arteanBinder Aglutinante AglutinatzaileBlade Cuchilla HortzBlasting Chorreado JariaketaBleached muslin Muselina blanqueada Muselina zurituaBond Enlace LoturaBone Hueso HezurBrittle Frágil HauskorBuffing Abrillantado DistiraketaBurr Rebaba BizarCamshaft Arbol de levas Espeka ardatzaCarborundum Carborundo KarborundumCarriage Carro Orga

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GLOSSARY

by Endika Gandarias


Carrier Transportador / Portador GarraiatzaileCasting Fundición GaldaketaCenterless grinding Rectificado sin centros Zentrugabeko artezketaChip Viruta TxirbilChuck Amarre / Porta Amarratze / PortaCoarse Basto BaldarCoated abrasive Papel / telas abrasivas Paper / Oihal urratzaileakCompound Mezcla / Compuesto NahasteCorundum Corindón KorindoiCotton Algodón KotoiCrankshaft Cigüeñal BirabarkiCreep feed grinding Rectificado de profundidad Sakonerako artezketaCross-hatched Estrías cruzadas Ildaska gurutzatuakCup Copa KopaCutting speed Velocidad de corte Ebaketa abiaduraCutting speed Velocidad de corte Ebaketa abiadura

Descaling Descascarillar / Desescamar / Desincrustar / Decapar Azala kendu / Ezkata kendu / Inkrustazioak kendu / Ugerra kendu

Dressing Reavivado BerpizketaDrive spindle Cabezal motriz Buru eragileaEmery Esmeril EsmerilEmery cloth Paño de lija Lixa oihalEngine Motor MotoreFabric Tela OhialFace plate Plato plano Plater lauaFeed rate Avance por minuto Aitzinamendua minutukoFelt Fieltro FeltroField Campo EremuFirearms Armas de fuego Su arma

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GLOSSARY

by Endika Gandarias


Flannel Franela FlanelaFlat grinding Rectificado plano Artezketa lauaFloat Flotador FlotatzaileForming Conformado KonformaketaGage Calas patrón / Calzo Kala patroi / AltxagarriGear Engranaje EngranaiGearbox Caja de cambios Engranai kaxaGlue Pegar ItsatsiGolf clubs Palos de golf Golf makilakGrain Grano GranuGrinding Rectificado ArtezketaGrinding wheel Muela abrasiva Harri urratzaileGrit Grano abrasivo Ale urratzaileGroove Ranura ArtekaGround Rectificado ArteztutakoGuard Protector BabesHardness Dureza GogortasunaHeadstock Cabezal BuruHeater Calentador BerogailuHoning Bruñido TxartaketaHousing Carcasa KarkasaIdler pulley Rodillo tensor Tentsio arrabolaInfeed Avance AitzinamenduLapping Lapeado LapeaketaLay pattern Marca dejada Utzitako markaLeather Cuero LarruLinen Lino LihoLoose Suelto Aske

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GLOSSARY

by Endika Gandarias


Luster Lustre DistiraMagnet Imán ImanMandrel Mandril MandrilNarrow Estrecho EstuNonabrading No desgastable Higatu ezinNozzle Boquilla Aho / PitaPad Almohadilla KuxinPath Trayectoria IbilbidePeening Granallado GranailaketaPlaten Platina / Pieza soporte Platina / EuskarriPlunge grinding Rectificado por penetración Sakontze artezketaPolishing Pulido LeunketaProfile grinding Rectificado de perfiles Profilen artezketaProp Utillaje TresneriPump Bomba BonbaPutty Masilla MasillaRack Estante / Colgador KakoRadiusing Redondeo BiribiltzeRake Desprendimiento JaulkitzeRayon Rayón / Seda sintética Rayon / Zeta sintetikoRegulating wheel Muela reguladora Harri erregulatzaileaRemoval rate Tasa de eliminación Ezabapen tasaRidge Cresta Tontor / GandorRim Borde ErtzRing Aro UztaiRod Barra calibrada Baraila kalibratuaRoll Rodillo ArrabolRubber Goma / Caucho Goma / Kautxu

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GLOSSARY

by Endika Gandarias


Rust Óxido OxidoSaddle Asiento OinarriSandpaper Papel de lija Lixa paperScale Cascarilla Scratch Raya / Rasguño ArraiaShaft Barra BarailaSheet metal processes Transformación de chapa Txapa bidezko eraldaketaSlurry Lodo LokatzSmoothing Suavizado LeunketaSpindle Cabezal BuruSpindle speed Velocidad de giro Biraketa abiaduraStain Mancha OrbanStep Escalón MailakatuStone Piedra HarriStroke Trazado / Desplazamiento Marratze / DesplazamenduSuperfinishing Superacabado SuperakaberaTailstock Contrapunto KontrapuntuThread Roscado HariztaketaThrough-feed grinding Rectificado pasante Alderik aldeko artezketaTip Punta PuntaToolholder Portaherramientas Erraminta etxeaToughness Tenacidad ZailtasunTraverse grinding Rectificado transversal Zeharkako artezketaTruing Perfilado PerfilaketaVoid Vacío HutsuneWire brushing Desbarbado / Cepillado con alambre Bizar kentzeWorkpiece Pieza PiezaWorktable Mesa de trabajo Lan mahai

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GLOSSARY

by Endika Gandarias


Worm Sin fín Sin fin

Engineering

Abrasive technologies