Post on 07-Feb-2017
BACHELOR OF ENGINEERING
MANUFACTURING TECHNOLOGIES
MACHINING TIME & COST ESTIMATION
by Endika Gandarias
2 by 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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CONTENTS
BIBLIOGRAPHY INTRODUCTION MACHINING COST ESTIMATION MACHINING TIME CUTTING PARAMETERS GLOSSARY
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
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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:
by Endika Gandarias
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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
by Endika Gandarias
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MACHINING COST ESTIMATION
• 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.
MACHINING COST ESTIMATION
ANALYTIC Cost Estimation
by Endika Gandarias
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ANALYTIC Cost Estimation
MACHINING 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
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
𝑇𝑆𝐸𝑇−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
MACHINING TIME ESTIMATION METHODS
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MACHINING TIME ESTIMATION METHODS
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
MACHINING TIME ESTIMATION METHODS
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.
Ó
¿Qué haremos ahora? Bueno, empezaremos a
preparar la máquina
LISTADO DE OPERACIONES
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.
TIEMPO TOTAL = 38 MIN 50 SEG
MACHINING TIME ESTIMATION METHODS
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.
MACHINING TIME ESTIMATION METHODS
By the sum of elementary predefined times
Technical specifications Predefined elementary times by Endika Gandarias
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MACHINING TIME
TURNING MILLING
PERIPHERAL OR SIDE MILLING TURNING FACING FACE MILLING
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
DRILLING
by Endika Gandarias
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MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
TURNING - Turning
C
Pϕ
ϕ
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
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
TURNING - Turning
by Endika Gandarias
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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.
SOLUTION: TCUTTING = 14,71 min
MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
TURNING - Turning
by Endika Gandarias
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MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
TURNING - Facing
C
R ϕL
• r
C
Pϕ
by Endika Gandarias
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.
SOLUTION: TCUTTING = 144,12 min
MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
TURNING - Facing
by Endika Gandarias
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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.
For additional cutting data, please refer to “Cutting parameters” section at the end of this presentation.
SOLUTION: TCUTTING = 72,5 min
MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
TURNING - Facing
by Endika Gandarias
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MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
MILLING – Peripheral or side milling
by Endika Gandarias
L L
L
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MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
MILLING – Face milling It 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.
For additional cutting data, please refer to “Cutting parameters” section at the end of this presentation.
SOLUTION: TCUTTING = 14,92 min
by Endika Gandarias
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MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
DRILLING
H 2Hc
r
by Endika Gandarias
L
L =
==
L
nnVLT
ac
........................................................................................
...................................................·
l
c
L
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MACHINING TIME
CUTTING TIME CALCULUS (𝑇𝐶𝑈𝑇𝑇𝐼𝑁𝐺)
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.
For additional cutting data, please refer to “Cutting parameters” section at the end of this presentation.
SOLUTION: TCUTTING = 1,55 min
by Endika Gandarias
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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 – 40 A 40 - 50
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 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
Boring D 20 – 30 A 30 - 40
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 0.2-0.8
HARD METAL
Turning and facing D 80 – 100 A 100 - 120
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 0.2-0.8
Parting and grooving 60 – 80 0.04 – 0.1
Threading 40 - 50 Thread pitch According to formula
Drilling 30 – 40 Manual
Boring D 70 – 90 A 90 - 110
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 0.2-0.8
ALUMINIUM
HIGH SPEED STEEL (HSS)
Turning and facing D 40 – 60 A 60 - 80
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 0.2-0.8
Parting and grooving 20 – 30 0.02 – 0.1
Threading 15 Thread pitch According to formula
Drilling 30 Manual
Knurling 20
Boring D 30 – 50 A 50 - 70
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 0.2-0.8
HARD METAL
Turning and facing D 150 – 180 A 180 – 200
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 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
Boring D 140 – 170 A 170 - 190
D 0.1– 0.25 A 0.02/ 0.1
D 0.75-2 A 0.2-0.8
by Endika Gandarias
D: Roughing operation A: Finishing operation
CUTTING PARAMETERS: TURNING
41 by Endika Gandarias
MACHINE WORKPIECE MATERIAL
TOOL MATERIAL OPERATION Vc
(m/min) fz
(mm/tooth*rev) Ap
(mm) Ae
(mm)
MILLING MACHINE
STEEL
HIGH SPEED STEEL (HSS)
Face milling D 20 - 25 A 25 - 30
0.05 – 0.1 0.01 – 0.05
D 1-2 A 0.2-0.5
D (~2/3)Ø A (~2/3)Ø
Side milling D 20 - 25 A 25 - 30
0.05 – 0.1 0.01 – 0.05
D (50%-80%)Ø A (50%-80%)Ø
D (10%-25%)Ø A (5%-10%)Ø
Other milling D 15 - 20 A 20 - 25
0.05 – 0.1 0.01 – 0.05
HARD METAL
Face milling D 80 - 100
A 100 – 120 0.05 – 0.1 0.01 – 0.05
D 1-2 A 0.2-0.5
D (~2/3)Ø A (~2/3)Ø
Side milling D 80 - 100
A 100 – 120 0.05 – 0.1 0.01 – 0.05
D (50%-80%)Ø A (50%-80%)Ø
D (10%-25%)Ø A (5%-10%)Ø
Other milling D 70 - 90
A 90 – 100 0.05 – 0.1 0.01 – 0.05
ALUMINIUM
HIGH SPEED STEEL (HSS)
Face milling D 50 - 70 A 70 - 90
0.05 – 0.1 0.01 – 0.05
D 1-2 A 0.2-0.5
D (~2/3)Ø A (~2/3)Ø
Side milling D 50 - 70 A 70 - 90
0.05 – 0.1 0.01 – 0.05
D (50%-80%)Ø A (50%-80%)Ø
D (10%-25%)Ø A (5%-10%)Ø
Other milling D 40 - 60 A 60 - 70
0.05 – 0.1 0.01 – 0.05
HARD METAL
Face milling D120 - 150 A 150 – 180
0.05 – 0.1 0.01 – 0.05
D 1-2 A 0.2-0.5
D (~2/3)Ø A (~2/3)Ø
Side milling D120 - 150
A 150 – 180 0.05 – 0.1 0.01 – 0.05
D (50%-80%)Ø A (50%-80%)Ø
D (10%-25%)Ø A (5%-10%)Ø
Other milling D100 - 130
A 130 – 150 0.05 – 0.1 0.01 – 0.05
Other milling: slot milling, t-shape milling, dovetail milling, form milling. D: Roughing operation A: Finishing operation
CUTTING PARAMETERS: MILLING
42 by Endika Gandarias
MACHINE WORKPIECE MATERIAL
TOOL MATERIAL OPERATION Vc
(m/min) fn
(mm/rev)
DRILLING MACHINE
STEEL HIGH SPEED STEEL
(HSS)
Spot drilling 18 0.04 – 0.1 Drilling 18 0.04 – 0.1 Counterboring 9 Countersinking 9
ALUMINIUM HIGH SPEED STEEL
(HSS)
Spot drilling 30 – 40 0.04 – 0.1 Drilling 30 – 40 0.04 – 0.1 Counterboring 15 – 20 Countersinking 15 – 20
CUTTING PARAMETERS: DRILLING
ROUGHING FINISHING
Vc
fn
fz
F ap
ae
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GLOSSARY
by Endika Gandarias
ENGLISH SPANISH BASQUE
Aim Pretender / Aspirar a Asmoa izan Alloy Aleación Aleazio Assembly Ensamblaje Muntaia Axial cutting depth Profundidad de pasada axial Sakontze sakonera Bar Barra Baraila Batch Lote Sorta Blackout Apagón eléctrico Itzalaldi Boring Mandrinado Mandrinaketa Brass Latón Letoi Breakage Rotura Matxura Breakdown Rotura Matxura Business Negocio Negozio Cat iron Fundición / Hierro fundido Burdinurtu / Fundizio Copper Cobre Kobre Counterboring Lamado Lamaketa Countersinking Avellanado Abeilanatu Customer Cliente Bezero Cutting speed Velocidad de corte Ebaketa abiadura Dealership Franquicia Frankizia Delivery Entrega Emate Dovetail Cola de milano Mirubuztan Drilling Taladrado Zulaketa Expense Gasto Gastu Face milling Planeado Lauketa Facing Refrentado Aurpegiketa Feasible Viable Bideragarri Feed per revolution Avance por vuelta Aitzinamendua birako Feed per tooth Avance por diente Aitzinamendua hortzeko
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GLOSSARY
by Endika Gandarias
ENGLISH SPANISH BASQUE
Feed rate Avance por minuto Aitzinamendua minutuko Finishing Acabado Akabera Foil Lámina / Hoja / Papel Xafla mehe / Orri Glass Vidrio Beira Gray cast iron Fundición gris Burdiurtu grisa Grinding Rectificado Artezketa Grooving Ranurado Artekaketa Hard metal Metal duro Metal gogorra High Speed Steel (HSS) Acero rápido Altzairu lasterra Ingot Lingote Lingote Knurling Moleteado Moletaketa Lathe Torno Tornua Lowercase Minúscula Letra xehe Manufacture Fabricación Fabrikazio Nose radius Radio de punta Muturreko erradioa Parting Tronzado Trontzaketa Pitch Paso Neurri Planing Cepillado Arrabotaketa Powder Polvo Hauts Procurement Adquisición / Compra Erosketa Profit Beneficio Onura Purchase Compra Erosketa Radial cutting depth Profundidad de pasada radial / ancho de pasada Iraganaldi zabalera Rate Tasa Tasa Raw Bruto Landugabe Reaming Escariado Otxabuketa Rod Barra calibrada Baraila kalibratua Rough Basto Trauskil
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GLOSSARY
by Endika Gandarias
ENGLISH SPANISH BASQUE
Roughing Desbaste Arbastaketa Rubber Goma / Caucho Goma / Kautxu Sale Venta Salmenta Scope Especificaciones Zehaztapen Set-up Puesta a punto Doikuntza Shape Forma Itxura Shaping Limado Karrakatze Sheet Lámina Xafla Slot milling Ranurado Artekaketa Spindle speed Velocidad de giro Biraketa abiadura Spot drilling Punteado Punteaketa Stage Etapa Etapa Stainless Steel Acero inoxidable Altzairu erdoilgaitz Steel Acero Altzairu Supplier Proveedor Hornitzaile Teeth Dientes Hortzak Threading Roscado Hariztaketa Timing Cronometraje Kronometraje Toolhonding device Sistema de amarrar herramientas Erramintak lotzeko sistemak Tubing Tubo Tutu Tungsten carbide Carburo de tungsteno Tungsteno karburoa Turning Torneado Torneaketa Twist drill Broca helicoidal Barauts helikoidala Unforeseen Imprevisto Aurreikusi gabeko Wear Desgaste Higadura Weight Peso Pisu Wire Alambre Burdin hari Workholding device Sistema de amarrar piezas Piezak lotzeko sistemak