Machining time and costs

BACHELOR OF ENGINEERINGBACHELOR OF ENGINEERING

MANUFACTURING TECHNOLOGIESMANUFACTURING TECHNOLOGIES

MACHINING TIME MACHINING TIME & COST ESTIMATION & COST ESTIMATION

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

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CONTENTSBIBLIOGRAPHYINTRODUCTIONMACHINING COST ESTIMATIONMACHINING TIMECUTTING PARAMETERSGLOSSARY

by Endika Gandarias

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BIBLIOGRAPHY

BIBLIOGRAPHY

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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

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INTRODUCTION

INTRODUCTION

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INTRODUCTION

• Any product or service that aims to success in the market must fulfill the CUSTOMER demands:

• Product / service Quality

• Product / service Cost

• Product / service Delivery Time

• Consequently, it is essential for a company to differentiate from their competitors in one or more of these aspects:

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• When manufacturing a component, there is a strong relation among COST and:

• Material

• Process

• Design

• Assembly

INTRODUCTION

DFMA Design For Manufacturing and Assembly

analysis and optimization of these interrelations

Material

Design

Process

Assembly

COST

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• Thus, manufacturing department must be in close relation with all other departments in a company:

- Design dept. - Purchase dept.

- Quality dept. - Sales dept.

- Etc.

INTRODUCTION

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INTRODUCTION

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Material

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INTRODUCTION

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Process

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PROPOSED DESIGN

Looks OK,right?

INTRODUCTION

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Design

Assembly

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FINAL DESIGN

After DFMAwhat a difference!

INTRODUCTION

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Design

Assembly

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MACHINING COST ESTIMATION

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• COST ESTIMATION consists in calculating the costs of the product or/and services that a company offers.

• Most commonly used machining COST ESTIMATION methods are:

• PRIMA (PRocess Information Maps)

• Parametric calculation an estimation of manufacturing cost

• Analytic calculation a more precise cost calculation method

• WHY DO WE NEED TO DO A COST ESTIMATION METHOD?

• To identify if a new product is feasible or not, and to modify it in an early design stage.

• To define the product price.

• To verify offers obtained from different suppliers subcontracting

• To identify the most economical process to manufacture the product.

• To identify expenses and help in their minimization.

• To take strategical decissions: eliminate a product, subcontracting, discounts,…

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• As mentioned before, the price is defined by the market and not by our production/manufacuring cost.

• So we must always produce below the market price.

Direct cost + indirect cost + profit = product price ideal business

Direct cost + indirect cost = product price no profit

Direct cost + indirect cost < product price no business

• PROS:• It offers a very accurate estimation.

• CONS:• It is a time consuming cost estimation method.• A lot of data is necessary to feed the method.


ANALYTIC Cost Estimation

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ANALYTIC Cost Estimation


• In the ANALYTIC cost estimation, the final cost of the product is calculated by considering the real cost of all the steps/processes.

• Each step/ process adds a value to the final product but for doing so a cost is necessary.

• The main cost that are taken into consideration are as follows:

DIRECT COST (DC)

INDIRECT COST (IC)

• Material cost• Tooling cost• Manufacturing cost• Any subcontracting cost

• Commercial cost ( ~ %10 DC)• Indirect cost ( ~ %25 DC)

DESIRED PROFIT( ~ %15 (DC + IC))

PRODUCT TOTAL PRICE +

+

by Endika Gandarias

Machining time calculus is required.

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MACHINING TIME

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MACHINING TIME

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MACHINING TIME

MACHINING TIME ESTIMATION METHODS

by Endika Gandarias

• The TOTAL MACHINING TIME (TT) calculus is very important to determine:• Manufacturing costs: Machine rate [€/h] * TT [h]• Machine work loads• Personnel needs.• Delivery time

• The cutting time (TCUTTING) is the only one that can be accurately calculated. Rest of the times need to be estimated.

• Most commonly used TIME ESTIMATION methods are:1. By estimation.2. By comparison.3. By timing.4. By the sum of elementary predefined times.

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MACHINING TIME

• Time necessary to prepare the machine-tool to be ready to start machining:

• Workholding device set-up

• Toolholding device set-up

• Material procurement

• Tool procurement

𝑇 −𝑆𝐸𝑇 𝑈𝑃 : Set-up time 𝑇MANUAL OPERATION : Manual operation time

• It is difficult to calculate properly because it varies depending on part’s dimensions and weight, machine tool, etc.

• In general, manual operation time > cutting time.

• Workpiece clamping and un-clamping

• Non-cutting movements

• Tool changes

• Taking references

• Measurements

𝑇CUTTING : Cutting time 𝑇UNFORESEEN : Unforeseen time

• It is the time consumed in movements that remove material.

• Non-cutting movements, such as fast approximations or retracts, are not considered.

L: tool or workpiece displacement.

V: displacement speed.

• It covers all the time gone in unforeseeable events during the machining process (unexpected times).

• Machine-tool breakdown.

• Tool wear or breakage

• Lack of raw material.

• Blackout


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MACHINING TIME

• It consists in breaking down the operation in different smaller phases, so that a rough estimation can be made based on the experience of the technicians.

• It is commonly used when:• unitary parts or small batches are required.• not enough data is available.• delivery time is short.

• As it is a estimation method, it is not very accurate.

BASED ON THE TECHNICIAN EXPERIENCE

By estimation

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• It consists in determining the time of a specific operation by comparing it with the time consumed a previously machined similar operation.

• As it is a estimation method, it is not very accurate. However, it is more accurate than the estimation method.

BASED ON OTHER PARTS EXPERIENCE

MACHINING TIME


By comparison

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MACHINING TIME

BASED ON THE TIMING

1ª OPERACIÓN HABLAR Los operarios antes de comenzar el proceso comentan entre ellos sobre el trabajo que habrán de desempeñar DURACIÓN= 30 Seg.

2ª OPERACIÓN LIMPIAR Con el propósito de eliminar los restos que hayan podido quedar del trabajo realizado en el proceso anterior, es muy importante limpiar bien la prensa DURACIÓN = 1Min 20 Seg. 3ª OPERACIÓN TRAER LOS ELEMENTOS El operario traerá los soportes para iniciar el cambio

DURACIÓN = 40 SEG.

¿Qué haremos ahora? Bueno, empezaremos a

preparar la máquina

LISTADO DE OPERACIONES

TIEMPO TOTAL = 38 MIN 50 SEG

OPERACIÓN TIEMPO 1 Hablar 0 min 30 seg 2 Limpiar 1 min 20 seg 3 Traer los elementos 0 min 40 seg 4 Parar la prensa y limpiar los bajos de la estampa 0 min 40 seg 5 Limpiar la trasera de la prensa 2 min 00 seg 6 Ir en busca de la maza y del cabezal 0 min 34 seg 7 Extraer la cuña 3 min 24 seg 8 Colocar los rodillos y extraer el molde 1 min 15 seg 9 Coger la grúa y enganchar 1 min 10 seg 10 Trasladar la estampa vieja 0 min 45 seg 11 Traer la estampa nueva 1min 00 seg 12 Llevar los elementos 0 min 15 seg 13 Atar la prensa nueva 3 min 00 seg 14 Retirar los rodillos elementos y devolverlos 1 min 15 seg 15 Ajustar la estampa para meter bien la chapa 2 min 30 seg 16 Ir a por la cuña y volver 0 min 21 seg 17 Hablar con el encargado 0 min 30 seg 18 Meter la cuña 0 min 40 seg 19 Atar las bridas delanteras y traseras 1 min 52 seg 20 Regular en altura 0 min 12 seg 21 Embridar la parte delantera y trasera 0 min 52 seg 22 Tocar con el tope la altura 0 min 55 seg 23 Apretar 0 min 20 seg 24 Revisar la carrera 4 min 20 seg 25 Hacer pruebas 2 min 00 seg 26 Aguardar la 1ª pieza 1 min 00 seg 27 Primera prueba 0 min 30 seg 28 Aguardar la 2ª pieza 2 min 00 seg 29 Segunda prueba 0 min 20 seg 30 Comprobar si está bien 0 min 20 seg 31 Apretar todo adecuadamente 2 min 20 seg

• It consists in measuring the time needed to manufacture the part.

• Thus, it is a very time consuming and expensive method.

• It is commonly used when:• Very stable & automatized processes are required. • Large series are required.

LISTADO DE OPERACIONES

TIEMPO TOTAL = 38 MIN 50 SEG


By timing

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MACHINING TIME

• It consists in breaking down the execution of a part in elementary phases. The time needed to be accomplish these elementary phases are predefined in tables (machine notebooks).

• It is commonly used when a fast and economic decision need to be taken.

• It is an accurate time estimation method.


By the sum of elementary predefined times

Technical specifications Predefined elementary timesby Endika Gandarias

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MACHINING TIME

TURNING MILLING

PERIPHERAL OR SIDE MILLINGTURNING FACING FACE MILLING

CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)

DRILLING

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MACHINING TIME


TURNING - Turning

C

P

L c

P

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Calculate the cutting time needed to finish turning a Ø60 mm steel part down to Ø59.6 mm in a length of 60 mm if a tungsten carbide tool main positioning angle of 45º is used.

The cutting speed is 120 m/min, the cutting depth 0.2mm, the feed per revolution 0.2 mm/rev and the safety distance 2 mm.

SOLUTION: TCUTTING = 0,49 min

MACHINING TIME


TURNING - Turning

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A part of Ø60 mm is aimed to be achieved after making successive rough turning operations and starting from an aluminium bar of Ø75 mm. The tool is made of High Speed Steel and the tool main positioning angle is 60º.

If a cutting speed of 40 m/min, a feed per revolution of 0.25 mm/rev, a cutting length of 120 mm and a cutting depth of 1.5 mm is used, calculate the machining time considering an entry and exit security distance of 2mm.


MACHINING TIME


TURNING - Turning

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MACHINING TIME


TURNING - Facing

C

R L

•r

C

P

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r = tool nose radius

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The finish facing of a steel part of Ø300 mm is aimed to be machined in a lathe at a constant spindle speed.

Calculate the cutting time spent on the operation knowing that the HSS tool main positioning angle is 60°, the tool nose radius is 0.8 mm and the entry security distance is 2mm.

For additional cutting data, please refer to “Cutting parameters” section at the end of this presentation.


MACHINING TIME


TURNING - Facing

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An aluminium part of Ø300 mm and a length of 150 mm will be machined using a rough facing operation in a lathe using a constant spindle speed, and its length is aimed to be shortened to 140 mm.

Calculate the cutting time spent on the operation knowing that the main HSS tool positioning angle is 60°, the tool nose radius is 0.8mm and the entry security distance is 2mm.



MACHINING TIME


TURNING - Facing

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MACHINING TIME


MILLING – Peripheral or side milling

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LL

L

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MACHINING TIME


MILLING – Face milling

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LL

L

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MACHINING TIME


MILLING – Face millingIt is aimed to machine a steel flat surface using a face milling tool. The surface to be machined is 100 mm wide by 300 mm length.

Determine the cutting time knowing that a finishing operation will be accomplished in a single cutting depth, the carbide tool diameter has 12 teeth and a Ø = 150 mm. The entry and exit security distance are 3mm.



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MACHINING TIME


DRILLING

H 2Hc

r

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L

L

L

nnVLTa

c

..... ........... ........ ..... ....... ...... ............. ....... ............ ...... ....... .

....... ..... ........ ..... ............ ..... ....... ..·

l

c

L

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MACHINING TIME


DRILLING

Determine the cutting time needed to drill the steel part of the figure, knowing that a rough operation will be carried out using a twist drill with a tip angle of H=118°. The entry and exit security distance are 3mm.



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CUTTING PARAMETERS

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CUTTING PARAMETERS

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CUTTING PARAMETERS

VARIABLE UNIT DESCRIPTION HOW TO CALCULATE? TURNING MILLING DRILLING

Vc m/min Cutting speed TABLES

N rpm or rev/min Spindle speed N=(Vc*1000)/(π*Ø)

fz mm/tooth*rev Feed per tooth TABLES

fn mm/rev Feed per revolution

TABLES

fn = fz * z

F mm/min Feed rate or feed per minute

F = fn * N

Ap mm Axial cutting depth

TABLES

Tool radius

Ae mm Radial cutting depth TABLES

Parameter introduced into the machine.

Parameter NOT introduced into the machine.

SUMMARY TABLE

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MACHINE WORKPIECE MATERIAL TOOL MATERIAL OPERATION

Vc

(m/min)fn

(mm/rev)Ap

(mm)

TURNING MACHINE

STEEL

HIGH SPEED STEEL(HSS)

Turning and facing D 30 – 40A 40 - 50

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8

Parting and grooving 10 – 15 0.02 – 0.1

Threading 10 Thread pitch According to formula

Drilling 18 Manual

Knurling 10

BoringD 20 – 30A 30 - 40

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8

HARD METAL

Turning and facingD 80 – 100A 100 - 120

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8


Threading 40 - 50 Thread pitch According to formula

Drilling 30 – 40 Manual

BoringD 70 – 90A 90 - 110

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8

ALUMINIUM


Turning and facing D 40 – 60A 60 - 80

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8


Threading 15 Thread pitch According to formula

Drilling 30 Manual

Knurling 20

BoringD 30 – 50A 50 - 70

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8

HARD METAL

Turning and facingD 150 – 180A 180 – 200

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8

Parting and grooving 80– 100 0.04 – 0.1

Threading 50 – 60 Thread pitch According to formula

Drilling 60 – 80 Manual

BoringD 140 – 170A 170 - 190

D 0.1– 0.25 A 0.02/ 0.1

D 0.75-2A 0.2-0.8

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D: Roughing operationA: Finishing operation

CUTTING PARAMETERS: TURNING



Vc

(m/min)fz

(mm/tooth*rev)Ap

(mm) Ae

(mm)

MILLING MACHINE

STEEL


Face milling D 20 - 25 A 25 - 30

0.05 – 0.10.01 – 0.05

D 1-2A 0.2-0.5

D (~2/3)ØA (~2/3)Ø

Side milling D 20 - 25 A 25 - 30

0.05 – 0.10.01 – 0.05

D (50%-80%)ØA (50%-80%)Ø

D (10%-25%)ØA (5%-10%)Ø

Other milling D 15 - 20 A 20 - 25

0.05 – 0.10.01 – 0.05

HARD METAL

Face milling D 80 - 100

A 100 – 1200.05 – 0.1

0.01 – 0.05D 1-2

A 0.2-0.5D (~2/3)ØA (~2/3)Ø

Side millingD 80 - 100

A 100 – 1200.05 – 0.1

0.01 – 0.05D (50%-80%)ØA (50%-80%)Ø

D (10%-25%)ØA (5%-10%)Ø

Other millingD 70 - 90

A 90 – 1000.05 – 0.1

0.01 – 0.05

ALUMINIUM


Face milling D 50 - 70 A 70 - 90

0.05 – 0.10.01 – 0.05

D 1-2A 0.2-0.5

D (~2/3)ØA (~2/3)Ø

Side milling D 50 - 70 A 70 - 90

0.05 – 0.10.01 – 0.05

D (50%-80%)ØA (50%-80%)Ø

D (10%-25%)ØA (5%-10%)Ø

Other milling D 40 - 60 A 60 - 70

0.05 – 0.10.01 – 0.05

HARD METAL

Face milling D120 - 150 A 150 – 180

0.05 – 0.10.01 – 0.05

D 1-2A 0.2-0.5

D (~2/3)ØA (~2/3)Ø

Side millingD120 - 150

A 150 – 1800.05 – 0.1

0.01 – 0.05D (50%-80%)ØA (50%-80%)Ø

D (10%-25%)ØA (5%-10%)Ø

Other millingD100 - 130

A 130 – 1500.05 – 0.1

0.01 – 0.05

Other milling: slot milling, t-shape milling, dovetail milling, form milling.D: Roughing operationA: Finishing operation

CUTTING PARAMETERS: MILLING



Vc

(m/min)fn

(mm/rev)

DRILLING MACHINE

STEELHIGH SPEED STEEL

(HSS)

Spot drilling 18 0.04 – 0.1Drilling 18 0.04 – 0.1Counterboring 9 Countersinking 9

ALUMINIUMHIGH SPEED STEEL

(HSS)

Spot drilling 30 – 40 0.04 – 0.1Drilling 30 – 40 0.04 – 0.1Counterboring 15 – 20 Countersinking 15 – 20

CUTTING PARAMETERS: DRILLING

ROUGHING FINISHING

Vc

fn

fz

Fap

ae

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GLOSSARY

GLOSSARY

by Endika Gandarias

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GLOSSARY

by Endika Gandarias

ENGLISH SPANISH BASQUE

Aim Pretender / Aspirar a Asmoa izanAlloy Aleación AleazioAssembly Ensamblaje MuntaiaAxial cutting depth Profundidad de pasada axial Sakontze sakoneraBar Barra BarailaBatch Lote SortaBlackout Apagón eléctrico ItzalaldiBoring Mandrinado MandrinaketaBrass Latón LetoiBreakage Rotura MatxuraBreakdown Rotura MatxuraBusiness Negocio NegozioCat iron Fundición / Hierro fundido Burdinurtu / FundizioCopper Cobre KobreCounterboring Lamado LamaketaCountersinking Avellanado AbeilanatuCustomer Cliente BezeroCutting speed Velocidad de corte Ebaketa abiaduraDealership Franquicia FrankiziaDelivery Entrega EmateDovetail Cola de milano MirubuztanDrilling Taladrado ZulaketaExpense Gasto GastuFace milling Planeado LauketaFacing Refrentado AurpegiketaFeasible Viable BideragarriFeed per revolution Avance por vuelta Aitzinamendua birakoFeed per tooth Avance por diente Aitzinamendua hortzeko

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GLOSSARY

by Endika Gandarias


Feed rate Avance por minuto Aitzinamendua minutukoFinishing Acabado AkaberaFoil Lámina / Hoja / Papel Xafla mehe / OrriGlass Vidrio BeiraGray cast iron Fundición gris Burdiurtu grisaGrinding Rectificado ArtezketaGrooving Ranurado ArtekaketaHard metal Metal duro Metal gogorraHigh Speed Steel (HSS) Acero rápido Altzairu lasterraIngot Lingote LingoteKnurling Moleteado MoletaketaLathe Torno TornuaLowercase Minúscula Letra xeheManufacture Fabricación FabrikazioNose radius Radio de punta Muturreko erradioaParting Tronzado TrontzaketaPitch Paso NeurriPlaning Cepillado ArrabotaketaPowder Polvo HautsProcurement Adquisición / Compra ErosketaProfit Beneficio OnuraPurchase Compra ErosketaRadial cutting depth Profundidad de pasada radial / ancho de pasada Iraganaldi zabaleraRate Tasa TasaRaw Bruto LandugabeReaming Escariado OtxabuketaRod Barra calibrada Baraila kalibratuaRough Basto Trauskil

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GLOSSARY

by Endika Gandarias


Roughing Desbaste ArbastaketaRubber Goma / Caucho Goma / KautxuSale Venta SalmentaScope Especificaciones ZehaztapenSet-up Puesta a punto DoikuntzaShape Forma ItxuraShaping Limado KarrakatzeSheet Lámina XaflaSlot milling Ranurado ArtekaketaSpindle speed Velocidad de giro Biraketa abiaduraSpot drilling Punteado PunteaketaStage Etapa EtapaStainless Steel Acero inoxidable Altzairu erdoilgaitzSteel Acero AltzairuSupplier Proveedor HornitzaileTeeth Dientes HortzakThreading Roscado HariztaketaTiming Cronometraje KronometrajeToolhonding device Sistema de amarrar herramientas Erramintak lotzeko sistemakTubing Tubo TutuTungsten carbide Carburo de tungsteno Tungsteno karburoaTurning Torneado TorneaketaTwist drill Broca helicoidal Barauts helikoidalaUnforeseen Imprevisto Aurreikusi gabekoWear Desgaste HigaduraWeight Peso PisuWire Alambre Burdin hariWorkholding device Sistema de amarrar piezas Piezak lotzeko sistemak

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GLOSSARY

by Endika Gandarias


Wrought Worked Landua

Machining time and costs

Engineering

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