1) The document discusses metal cutting processes and machine tools. It describes different types of machining operations like turning, milling, drilling etc.
2) It explains concepts like shear angle, cutting forces, tool geometry specifications and factors affecting chip formation. Diagrams of tool geometry and forces on cutting tool are provided.
3) Equations to calculate shear angle, cutting forces and power are derived based on Merchant's metal cutting theory which involves minimum energy principle and assumes work material behaves plastically.
This document discusses optimization of cutting conditions for metal cutting operations. It introduces key factors like cutting speed, feed rate, and tool life that impact production time and cost. Equations are presented to calculate the optimum cutting speed and tool life that give minimum production cost and time. The relationships between these variables are illustrated with graphs. The document also provides examples of how to estimate costs for machine tools, operators, and tools to determine optimal cutting conditions for a given machining operation.
This slide is all about Metal cutting and Machining tools insights. It covers Mechanics of metal cutting, orthogonal and oblique machining, Tools geometry, Types of Chips, and Tools Signature.
This document provides an overview of workholding methods, specifically focusing on jigs and fixtures. It discusses the history and evolution of workholding, from early templates to modern jigs and fixtures. The key differences between jigs and fixtures are explained, with jigs guiding cutting tools and fixtures referencing them. Different types of permanent, temporary, and modular workholders are described. The document considers various design factors for workholders, such as tooling costs, details, operation, and safety. A variety of applications for jigs and fixtures in machining and other manufacturing operations are also mentioned.
This document provides an overview of machining fundamentals including chip formation, cutting temperatures, cutting forces, power requirements, and definitions of key terms. It covers topics such as orthogonal and oblique cutting, chip types, heat distribution from cutting, formulas for calculating cutting forces and power in turning, milling, and drilling, and examples of calculating cutting forces and power for given operations. It also includes a glossary translating machining terms between English, Spanish, and Basque.
This document describes the key components and geometry of a single point cutting tool. A single point cutting tool has a shank that fits into the tool holder, a face along which chips slide upwards, and two cutting edges - a side cutting edge and an end cutting edge where material is removed. It also has flank surfaces below the cutting edges and a nose or cutting point where the edges intersect. The document outlines the various angles of a single point cutting tool, including the end cutting edge angle, side cutting edge angle, back rake angle, and relief angles, which are important for tool function. Tool shape is specified using a signature that lists the numerical values of these angles and the nose radius.
This document discusses various work holding devices used on lathes: three jaw chucks and four jaw chucks for holding cylindrical stock, collet chucks for small parts, and magnetic chucks for thin pieces. Lathe centers provide support between centers, while lathe dogs provide a firm connection between spindle and workpiece. Mandrels hold hollow or drilled workpieces. Rests provide extra support for long workpieces. Face plates allow irregularly shaped pieces to be mounted on the lathe headstock.
The document provides information about tool wear and tool life in machining processes. It discusses how tool wear occurs due to forces, temperature, and sliding action during cutting. The three main types of tool wear are flank wear, crater wear, and chipping. Flank wear is caused by abrasion from hard particles in the workpiece while crater wear results from high temperatures and diffusion at the tool-chip interface. Maintaining optimal cutting conditions and tool geometry can increase tool life. The document also covers tool materials, machinability factors, cutting fluids, machining forces, and lathe operations such as turning, facing, and threading.
Metal cutting involves removing unwanted material from a workpiece. In orthogonal cutting, the cutting tool edge is perpendicular to the direction of motion, so chip flow is perpendicular to the cutting edge. In oblique cutting, the cutting tool edge is at an angle to the direction of motion, so chip flow is sideways. Orthogonal cutting results in higher heat concentration, shorter tool life, and poorer surface finish than oblique cutting. Oblique cutting is used for most industrial processes like drilling and milling.
This document discusses optimization of cutting conditions for metal cutting operations. It introduces key factors like cutting speed, feed rate, and tool life that impact production time and cost. Equations are presented to calculate the optimum cutting speed and tool life that give minimum production cost and time. The relationships between these variables are illustrated with graphs. The document also provides examples of how to estimate costs for machine tools, operators, and tools to determine optimal cutting conditions for a given machining operation.
This slide is all about Metal cutting and Machining tools insights. It covers Mechanics of metal cutting, orthogonal and oblique machining, Tools geometry, Types of Chips, and Tools Signature.
This document provides an overview of workholding methods, specifically focusing on jigs and fixtures. It discusses the history and evolution of workholding, from early templates to modern jigs and fixtures. The key differences between jigs and fixtures are explained, with jigs guiding cutting tools and fixtures referencing them. Different types of permanent, temporary, and modular workholders are described. The document considers various design factors for workholders, such as tooling costs, details, operation, and safety. A variety of applications for jigs and fixtures in machining and other manufacturing operations are also mentioned.
This document provides an overview of machining fundamentals including chip formation, cutting temperatures, cutting forces, power requirements, and definitions of key terms. It covers topics such as orthogonal and oblique cutting, chip types, heat distribution from cutting, formulas for calculating cutting forces and power in turning, milling, and drilling, and examples of calculating cutting forces and power for given operations. It also includes a glossary translating machining terms between English, Spanish, and Basque.
This document describes the key components and geometry of a single point cutting tool. A single point cutting tool has a shank that fits into the tool holder, a face along which chips slide upwards, and two cutting edges - a side cutting edge and an end cutting edge where material is removed. It also has flank surfaces below the cutting edges and a nose or cutting point where the edges intersect. The document outlines the various angles of a single point cutting tool, including the end cutting edge angle, side cutting edge angle, back rake angle, and relief angles, which are important for tool function. Tool shape is specified using a signature that lists the numerical values of these angles and the nose radius.
This document discusses various work holding devices used on lathes: three jaw chucks and four jaw chucks for holding cylindrical stock, collet chucks for small parts, and magnetic chucks for thin pieces. Lathe centers provide support between centers, while lathe dogs provide a firm connection between spindle and workpiece. Mandrels hold hollow or drilled workpieces. Rests provide extra support for long workpieces. Face plates allow irregularly shaped pieces to be mounted on the lathe headstock.
The document provides information about tool wear and tool life in machining processes. It discusses how tool wear occurs due to forces, temperature, and sliding action during cutting. The three main types of tool wear are flank wear, crater wear, and chipping. Flank wear is caused by abrasion from hard particles in the workpiece while crater wear results from high temperatures and diffusion at the tool-chip interface. Maintaining optimal cutting conditions and tool geometry can increase tool life. The document also covers tool materials, machinability factors, cutting fluids, machining forces, and lathe operations such as turning, facing, and threading.
Metal cutting involves removing unwanted material from a workpiece. In orthogonal cutting, the cutting tool edge is perpendicular to the direction of motion, so chip flow is perpendicular to the cutting edge. In oblique cutting, the cutting tool edge is at an angle to the direction of motion, so chip flow is sideways. Orthogonal cutting results in higher heat concentration, shorter tool life, and poorer surface finish than oblique cutting. Oblique cutting is used for most industrial processes like drilling and milling.
This document is a series of lecture slides about sheet metal working and bending processes. It discusses topics like mechanics of sheet metal bending, bend allowance, numerical problems calculating blank size and bending force, springback and methods to eliminate it, including overbending and stretch forming. It also covers drawing as a sheet metal forming operation used to make cup-shaped or complex curved parts by pushing metal into a die cavity with a punch.
The document discusses machining processes and cutting tools. It provides definitions of machining and cutting tools. It describes:
- The importance of machining processes in manufacturing precise parts.
- Objectives of machining like high material removal rate and surface finish, low tool and power costs.
- Classification of cutting tools based on how relative motion is provided between tool and workpiece.
- Key terms related to cutting tool geometry like rake angle, relief angle, and their influence on tool strength and chip removal.
- Mechanism of chip formation and different types of chips produced.
Theory of metal cutting MG University(S8 Production Notes)Denny John
Theory of metal cutting MG University(S8 Production Notes)
Scenario of manufacturing process – Deformation of metals,
Schmid’s law (review only) – Performance and process parameters – single point cutting
tool nomenclature - attributes of each tool nomenclature - attributes of feed and tool
signature on surface roughness obtainable, role of surface roughness on crack initiation -
Oblique and orthogonal cutting – Mechanism of metal removal - Primary and secondary
deformation shear zones - Mechanism of chip formation, card model, types of chip,
curling of chips, flow lines in a chip, BUE, chip breakers, chip thickness ratio –
Mechanism of orthogonal cutting: Thin zone and thick zone, Merchant’s analysis – shear
angle relationship, Lee and Shaffer`s relationship, simple problems – Friction process in
metal cutting: nature of sliding friction, columb`s law, adhesion theory, ploughing, sublayer
flow – Empirical determination of force component.
MILLING – Cutting parameters, machine time calculation
Milling operation – Plain milling, side & face milling, form milling, gang milling, end milling, face milling, T slot milling, slitting
GEAR CUTTING – Gear cutting on milling machine – dividing head and indexing method, gear hobbing, principle of operation, advantages & limitation, hobbing tech, gear shaping, gear finishing process
This document discusses orthogonal and oblique cutting operations in turning. It defines:
- Orthogonal cutting as having the cutting edge travel perpendicular to the workpiece with perpendicular cutting forces.
- Oblique cutting as having the cutting edge travel at an angle to the workpiece normal with three mutually perpendicular forces.
It provides diagrams of the forces acting in orthogonal and oblique cutting. Key forces defined are feed force, radial force, and cutting force. It also defines terms like rake angle, shear angle, chip thickness, cutting velocity, metal removal rate, specific energy, and machining time.
The document concludes with a sample problem asking to determine values like shear angle, friction coefficient, shear stresses and
The document discusses cutting tool materials and Merchant's Circle Diagram (MCD) for calculating forces in machining. It provides information on 7 common cutting tool materials: high carbon steel, high speed steel, cast alloys, cemented carbides, coated carbides, ceramics, and diamonds. It also explains what MCD is and how it can be used graphically to calculate cutting, tangential, friction, normal, shear and normal shear forces from measured cutting forces. An example calculation using MCD is provided.
Factors affecting tool life in machining processesmohdalaamri
This document discusses factors that affect tool life in machining processes. It identifies the main factors as cutting tool geometry, material, characteristics, cutting conditions, workpiece material, and cutting fluid. Cutting tool geometry influences machined surface quality, productivity, chip control, and forces/temperatures. Cutting tool material and coatings must have properties like heat/wear resistance. Cutting conditions like depth of cut, feed rate, and cutting speed also impact tool life. Workpiece material properties and machinability affect tool performance. Cutting fluids provide lubrication, cooling and chip removal to extend tool life. Environmental impacts of fluids are also considered.
What does clamping mean in context of jigs and fixtures?
Principles of Clamping
Different types of Clamping Devices, their advantaged and disadvantages
Jigs and fixtures are devices used to securely hold or locate a workpiece in a machining process. A jig locates and guides a cutting tool, while a fixture secures a workpiece to a machine table. They both help improve accuracy and efficiency. Key components include a base, locators to precisely position the workpiece, and clamps to securely hold it in place against cutting forces. Common types of locators are cylindrical, conical, and V-shaped to accommodate varying workpiece sizes. General principles for jigs and fixtures are that they reduce idle time, enable clean machining, use standardized parts, allow for coolant flow, have hardened locating surfaces, prevent incorrect assembly, and securely position workpieces
This document discusses the theory of metal cutting. It covers topics such as tool geometry, chip formation, types of chips, tool wear, cutting fluids, and tool material selection. It describes the two main types of metal cutting processes as orthogonal and oblique cutting. Orthogonal cutting involves two forces while oblique cutting involves three forces. Chip formation occurs through shear deformation of the work material. The main types of chips are continuous, discontinuous, continuous with BUE, and serrated. Continuous chips form under conditions like small chip thickness and high cutting speed, while discontinuous chips occur when machining brittle materials.
Tool life is measured by the time period from when a tool starts cutting until failure or until it needs resharpening. Tool life can be measured in units of time, number of pieces cut, volume of material removed, or length of cut. Tools typically fail due to high temperatures, mechanical impacts, or gradual wear. Wear occurs on the flank and crater faces of tools and is caused by abrasion, diffusion, electrochemical reactions, and other mechanisms. Factors like cutting speed, workpiece properties, tool geometry, and cooling influence tool life.
The document discusses cutting tools and their properties. It describes different types of cutting tool materials like high-speed steel, cemented carbides, ceramics, and diamond. It explains cutting tool nomenclature and defines terms like rake angle, clearance angle, nose, and flank. It also discusses factors that affect tool life like cutting conditions, work material properties, and tool material.
MANUFACTURING PROCESS -1(cutting tool nomenclature)Parthivpal17
In this presentation you will learn about the CUTTING TOOL NOMENCLATURE.i.e, cutting tool materials, toolbits, factor affecting tools, characteristics of cutting tools.
This document discusses tolerances and limits in engineering. It explains that components are made within tolerances due to manufacturing variability. There is an acceptable tolerance zone between the upper and lower limits for a component's dimensions. Various types of fits between parts are classified based on the overlap of their tolerance zones, including clearance fits, transition fits, and interference fits. International tolerance grades define standard tolerance zones using numerical designations.
Broaching is a machining process that uses a toothed tool called a broach to remove material in a single pass. Broaching was first used in the 1850s and was commonly used to rifle gun barrels during World War 1. Broaching machines can perform horizontal, vertical, continuous, and rotary broaching. Broaching tools are designed based on the material, size and shape of the cut, required tolerances, and production rates. Broaching provides high production rates and accuracy for complex hole shapes and surfaces.
Classification of metal removal process and machines: Concept of generatrix and directrix Geometry of single point cutting tool and tool angles, tool nomenclature in ASA, ORS, NRS. Concept of orthogonal and oblique cutting, Mechanism of Chip Formation: Type of chips. Mechanics of metal cutting, interrelationships between cutting force, shear angle, strain and strain rate. Various theories of metal cutting, Thermal aspects of machining and measurement of chip tool interface temperature, Friction in metal cutting
This document discusses single point cutting tools. It describes the types of tools, tool geometry including angles and designations. It explains the effects that varying the back rake angle, side rake angle, relief angle, cutting edge angle, and nose radius have on machining. Finally, it lists common tool materials and provides brief conclusions and references.
this presentation tries to explain the various heat zones that are developed during the metal cutting process. furthermore, how much heat is dissipated from the various zones. lastly the possible methods of temperature reduction in brief.
Single point cutting tools have a shank, cutting part, and various angles that define their geometry. The rake and relief angles affect cutting forces and tool life. Rake angles control cutting forces, while relief angles provide clearance and prevent rubbing. Tool wear occurs through adhesion, abrasion, and diffusion, degrading the cutting edge over time. Tool life is measured by various criteria like cutting time or material removed before failure. Tool life decreases with higher cutting speeds and increases with lower depths of cut and feed rates. Proper selection of tool geometry and cutting conditions can optimize tool life.
The document discusses tool specification and chip formation mechanisms. It begins by outlining the American System for specifying tool angles such as rake, relief, and cutting edge angles. It then explains how each angle impacts cutting forces and tool strength. The document also describes the mechanics of chip formation, defining shear angle and relating it to tool rake angle. It outlines factors that influence chip type and discusses tool surfaces and reference planes. Finally, it covers tool wear mechanisms, tool life definitions, and factors that tool life depends on such as cutting speed, depth of cut, and feed rate.
This document is a series of lecture slides about sheet metal working and bending processes. It discusses topics like mechanics of sheet metal bending, bend allowance, numerical problems calculating blank size and bending force, springback and methods to eliminate it, including overbending and stretch forming. It also covers drawing as a sheet metal forming operation used to make cup-shaped or complex curved parts by pushing metal into a die cavity with a punch.
The document discusses machining processes and cutting tools. It provides definitions of machining and cutting tools. It describes:
- The importance of machining processes in manufacturing precise parts.
- Objectives of machining like high material removal rate and surface finish, low tool and power costs.
- Classification of cutting tools based on how relative motion is provided between tool and workpiece.
- Key terms related to cutting tool geometry like rake angle, relief angle, and their influence on tool strength and chip removal.
- Mechanism of chip formation and different types of chips produced.
Theory of metal cutting MG University(S8 Production Notes)Denny John
Theory of metal cutting MG University(S8 Production Notes)
Scenario of manufacturing process – Deformation of metals,
Schmid’s law (review only) – Performance and process parameters – single point cutting
tool nomenclature - attributes of each tool nomenclature - attributes of feed and tool
signature on surface roughness obtainable, role of surface roughness on crack initiation -
Oblique and orthogonal cutting – Mechanism of metal removal - Primary and secondary
deformation shear zones - Mechanism of chip formation, card model, types of chip,
curling of chips, flow lines in a chip, BUE, chip breakers, chip thickness ratio –
Mechanism of orthogonal cutting: Thin zone and thick zone, Merchant’s analysis – shear
angle relationship, Lee and Shaffer`s relationship, simple problems – Friction process in
metal cutting: nature of sliding friction, columb`s law, adhesion theory, ploughing, sublayer
flow – Empirical determination of force component.
MILLING – Cutting parameters, machine time calculation
Milling operation – Plain milling, side & face milling, form milling, gang milling, end milling, face milling, T slot milling, slitting
GEAR CUTTING – Gear cutting on milling machine – dividing head and indexing method, gear hobbing, principle of operation, advantages & limitation, hobbing tech, gear shaping, gear finishing process
This document discusses orthogonal and oblique cutting operations in turning. It defines:
- Orthogonal cutting as having the cutting edge travel perpendicular to the workpiece with perpendicular cutting forces.
- Oblique cutting as having the cutting edge travel at an angle to the workpiece normal with three mutually perpendicular forces.
It provides diagrams of the forces acting in orthogonal and oblique cutting. Key forces defined are feed force, radial force, and cutting force. It also defines terms like rake angle, shear angle, chip thickness, cutting velocity, metal removal rate, specific energy, and machining time.
The document concludes with a sample problem asking to determine values like shear angle, friction coefficient, shear stresses and
The document discusses cutting tool materials and Merchant's Circle Diagram (MCD) for calculating forces in machining. It provides information on 7 common cutting tool materials: high carbon steel, high speed steel, cast alloys, cemented carbides, coated carbides, ceramics, and diamonds. It also explains what MCD is and how it can be used graphically to calculate cutting, tangential, friction, normal, shear and normal shear forces from measured cutting forces. An example calculation using MCD is provided.
Factors affecting tool life in machining processesmohdalaamri
This document discusses factors that affect tool life in machining processes. It identifies the main factors as cutting tool geometry, material, characteristics, cutting conditions, workpiece material, and cutting fluid. Cutting tool geometry influences machined surface quality, productivity, chip control, and forces/temperatures. Cutting tool material and coatings must have properties like heat/wear resistance. Cutting conditions like depth of cut, feed rate, and cutting speed also impact tool life. Workpiece material properties and machinability affect tool performance. Cutting fluids provide lubrication, cooling and chip removal to extend tool life. Environmental impacts of fluids are also considered.
What does clamping mean in context of jigs and fixtures?
Principles of Clamping
Different types of Clamping Devices, their advantaged and disadvantages
Jigs and fixtures are devices used to securely hold or locate a workpiece in a machining process. A jig locates and guides a cutting tool, while a fixture secures a workpiece to a machine table. They both help improve accuracy and efficiency. Key components include a base, locators to precisely position the workpiece, and clamps to securely hold it in place against cutting forces. Common types of locators are cylindrical, conical, and V-shaped to accommodate varying workpiece sizes. General principles for jigs and fixtures are that they reduce idle time, enable clean machining, use standardized parts, allow for coolant flow, have hardened locating surfaces, prevent incorrect assembly, and securely position workpieces
This document discusses the theory of metal cutting. It covers topics such as tool geometry, chip formation, types of chips, tool wear, cutting fluids, and tool material selection. It describes the two main types of metal cutting processes as orthogonal and oblique cutting. Orthogonal cutting involves two forces while oblique cutting involves three forces. Chip formation occurs through shear deformation of the work material. The main types of chips are continuous, discontinuous, continuous with BUE, and serrated. Continuous chips form under conditions like small chip thickness and high cutting speed, while discontinuous chips occur when machining brittle materials.
Tool life is measured by the time period from when a tool starts cutting until failure or until it needs resharpening. Tool life can be measured in units of time, number of pieces cut, volume of material removed, or length of cut. Tools typically fail due to high temperatures, mechanical impacts, or gradual wear. Wear occurs on the flank and crater faces of tools and is caused by abrasion, diffusion, electrochemical reactions, and other mechanisms. Factors like cutting speed, workpiece properties, tool geometry, and cooling influence tool life.
The document discusses cutting tools and their properties. It describes different types of cutting tool materials like high-speed steel, cemented carbides, ceramics, and diamond. It explains cutting tool nomenclature and defines terms like rake angle, clearance angle, nose, and flank. It also discusses factors that affect tool life like cutting conditions, work material properties, and tool material.
MANUFACTURING PROCESS -1(cutting tool nomenclature)Parthivpal17
In this presentation you will learn about the CUTTING TOOL NOMENCLATURE.i.e, cutting tool materials, toolbits, factor affecting tools, characteristics of cutting tools.
This document discusses tolerances and limits in engineering. It explains that components are made within tolerances due to manufacturing variability. There is an acceptable tolerance zone between the upper and lower limits for a component's dimensions. Various types of fits between parts are classified based on the overlap of their tolerance zones, including clearance fits, transition fits, and interference fits. International tolerance grades define standard tolerance zones using numerical designations.
Broaching is a machining process that uses a toothed tool called a broach to remove material in a single pass. Broaching was first used in the 1850s and was commonly used to rifle gun barrels during World War 1. Broaching machines can perform horizontal, vertical, continuous, and rotary broaching. Broaching tools are designed based on the material, size and shape of the cut, required tolerances, and production rates. Broaching provides high production rates and accuracy for complex hole shapes and surfaces.
Classification of metal removal process and machines: Concept of generatrix and directrix Geometry of single point cutting tool and tool angles, tool nomenclature in ASA, ORS, NRS. Concept of orthogonal and oblique cutting, Mechanism of Chip Formation: Type of chips. Mechanics of metal cutting, interrelationships between cutting force, shear angle, strain and strain rate. Various theories of metal cutting, Thermal aspects of machining and measurement of chip tool interface temperature, Friction in metal cutting
This document discusses single point cutting tools. It describes the types of tools, tool geometry including angles and designations. It explains the effects that varying the back rake angle, side rake angle, relief angle, cutting edge angle, and nose radius have on machining. Finally, it lists common tool materials and provides brief conclusions and references.
this presentation tries to explain the various heat zones that are developed during the metal cutting process. furthermore, how much heat is dissipated from the various zones. lastly the possible methods of temperature reduction in brief.
Single point cutting tools have a shank, cutting part, and various angles that define their geometry. The rake and relief angles affect cutting forces and tool life. Rake angles control cutting forces, while relief angles provide clearance and prevent rubbing. Tool wear occurs through adhesion, abrasion, and diffusion, degrading the cutting edge over time. Tool life is measured by various criteria like cutting time or material removed before failure. Tool life decreases with higher cutting speeds and increases with lower depths of cut and feed rates. Proper selection of tool geometry and cutting conditions can optimize tool life.
The document discusses tool specification and chip formation mechanisms. It begins by outlining the American System for specifying tool angles such as rake, relief, and cutting edge angles. It then explains how each angle impacts cutting forces and tool strength. The document also describes the mechanics of chip formation, defining shear angle and relating it to tool rake angle. It outlines factors that influence chip type and discusses tool surfaces and reference planes. Finally, it covers tool wear mechanisms, tool life definitions, and factors that tool life depends on such as cutting speed, depth of cut, and feed rate.
M.P- II-UNIT I -THEORY OF METAL CUTTING.pptMohanumar S
This document provides an overview of the objectives and outcomes for the course 20ME403 Manufacturing Process - II. The key topics covered include the theory of metal cutting, construction and operation of various machine tools like lathes, milling machines, and grinding machines. It also discusses gear manufacturing processes and CNC programming. The objectives are for students to understand metal cutting principles, machine tool operations, and acquire the ability to apply these concepts in machining as well as develop CNC part programs.
1. The document discusses the theory of metal cutting, including mechanics of chip formation, types of chips, cutting tool materials, tool wear, and other related topics.
2. It describes the different types of tool wear that can occur, including flank wear which results from the gradual wearing away of the cutting edge, and crater wear.
3. The key factors that influence chip formation and tool wear are also examined, such as material properties, cutting conditions, tool geometry, and choice of cutting tool material.
Mechanics of chip formation, single point cutting tool, forces in machining, Types of chip, cutting
tools– nomenclature, orthogonal metal cutting, thermal aspects, cutting tool materials, tool wear,
tool life, surface finish, cutting fluids and Machinability
This document provides an overview of fundamental machining concepts. It defines machining as a process of finishing workpieces by gradually removing excess material in the form of chips using cutting tools. Key concepts discussed include the geometry of single point cutting tools, tool angles like rake and clearance angles, chip formation, different types of chips, and shear plane and angle. It also discusses tool signatures and terminology. The document aims to provide elementary treatment of metal cutting theory.
This document summarizes cutting tools used in machining processes. It discusses single point and multi-point cutting tools. Single point tools have a single cutting edge, such as lathe and planer tools, while multi-point tools have two or more cutting edges like milling cutters and drills. The document describes the geometry of single point tools including the shank, flank, face, base, heel, nose, and cutting edges. It also discusses the various tool angles used in single point tools and provides examples of machines that use multi-point tools like milling machines and broaching machines. Finally, it covers tool wear, failure modes, and compares characteristics of single and multi-point cutting tools.
This document provides an overview of machining technology and machine tools. It discusses various machining processes including subtractive processes where material is removed from a workpiece using tools. Lathes, mills, drills and other machine tools are described as examples of machines that perform subtractive machining. The document also covers topics such as tool geometry, chip formation, cutting forces, tool life and wear. Different types of chips, tool materials, tool angles and variables that influence machinability are defined.
Cutting processes remove material from a workpiece's surface by producing chips. Common machining operations include turning, cutting off, slab milling, and end milling. The objective of metal cutting is quick material removal, high surface finish, economy in tool cost, less power consumption, and minimum cycle time. Chips can be either discontinuous or continuous, depending on factors like tool geometry, cutting conditions, and material properties. Cutting forces include cutting, friction, and shear forces. Power in cutting is dissipated in shearing and at the tool-chip interface. High temperatures generated during cutting can adversely affect tool life and workpiece properties.
This document provides information on metal cutting processes and machining technology. It discusses:
- The purpose, principles, and definition of machining as a process to produce parts to desired dimensions and surface finish through chip removal.
- Classification of metal cutting processes as orthogonal or oblique cutting. It also discusses cutting tool angles like back rake angle and relief angles.
- Factors that affect cutting forces like rake angle, feed rate, and depth of cut.
- Tool designation systems like ASA and common tool materials like high-speed steel and cemented carbide.
- The mechanism of chip formation and different chip types like continuous, discontinuous, and chips with built-up edge
This document discusses tool geometry and signatures for single point cutting tools. It defines key tool angles such as rake angles, clearance angles, and cutting edge angles. Rake angles are provided for chip flow, while clearance angles avoid rubbing between the tool and workpiece. The document then explains ANSI tool signature standards and defines each element of a signature for a single point tool, including back rake angle, side rake angle, end and side relief angles, end and side cutting edge angles, and nose radius. An example signature of 0-7-6-8-15-16-0.8 is provided.
The document discusses metal cutting and machining processes. It defines material removal processes as shaping operations that remove material from a work part to achieve a desired geometry. The two main types are machining, using a sharp cutting tool, and abrasive processes, using abrasive particles. Machining is important because it can cut a variety of materials and produce complex part shapes and features like threads and holes. However, it wastes material in chips and can be time consuming. The document then discusses chip formation mechanisms and types of chips produced from different materials and cutting conditions. It also defines tool elements, angles, and different types of single-point and multi-point cutting tools.
This document discusses two types of metal cutting methods: orthogonal cutting and oblique cutting. Orthogonal cutting involves a perpendicular cutting edge where only two cutting force components act in a plane. Oblique cutting features an inclined cutting edge where three mutually perpendicular cutting force components act and the cutting edge may not clear the entire workpiece width. Examples of orthogonal cutting include lathe cut-off operations while oblique cutting includes farming and milling where multiple cutting edges are often involved.
The document discusses metal cutting and machining processes. It begins with an introduction to metal cutting and the reasons for adopting machining processes. It then describes the mechanics of chip formation during metal cutting and different types of cutting like orthogonal and oblique. The document also defines important machining terminology like tool nomenclature, tool angles, tool signature and different machining operations like turning, drilling and milling.
The document discusses the theory of metal cutting. It covers topics such as mechanics of chip formation, types of cutting tools and tool nomenclature, orthogonal and oblique cutting models, thermal aspects of machining, cutting forces, and tool wear. The key points are:
1) Metal cutting involves shear deformation and plastic flow of material to form chips that are removed from the workpiece.
2) Cutting tools have specific geometries and angles like rake angle, clearance angle, that impact the cutting process.
3) Orthogonal cutting is the simplest model that describes the mechanics of machining through shear plane analysis.
4) Heat is generated in three zones during cutting - shear plane, tool-
This document discusses chip formation and cutting tool geometry in metal cutting operations. It describes the mechanics of chip formation, where a wedge-shaped tool exerts pressure on the workpiece, inducing shear deformation and removing material in the form of chips. The types of chips formed depend on whether the material is ductile or brittle. Continuous, discontinuous, and continuous chips with built-up edges are discussed. The document also outlines the geometry of single point cutting tools, designation systems, types of rakes, orthogonal and oblique cutting methods, forces on tools, and the purpose and types of chip breakers used.
1. The document discusses the theory of metal cutting, including the chip formation process, types of chips, tool angles, tool wear mechanisms, tool materials, and cutting fluids.
2. Key aspects covered include the orthogonal cutting model, factors that influence chip type like tool angles and speeds/feeds, how tool angles impact forces and tool life, and common tool materials like HSS and cemented carbides and their characteristics.
3. Cutting fluids are discussed as being important to reduce heat at the tool-work interface and lubricate the process to increase tool life and improve surface finish. Their properties and common types used are also summarized.
The document discusses the theory of metal cutting. It defines key terms like cutting tool, machine tool, and chip formation. It describes different types of chips that can form during cutting like continuous, discontinuous, and built-up edge chips. It explains the orthogonal cutting model and important angles of cutting tools like rake angle and clearance angle. It discusses the chip formation process and variables that influence forces and power requirements during cutting.
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Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
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3. 33
Introduction
• Object of mfg process is to produce piece of specified shape
and material properties.
• Any of the following three type of operations may be
employed for the same:
1. Constant Mass Operation (Casting, rolling etc.)
2. Material Addition Operation (Welding, Bolting, riveting etc)
3. Material Removal Operation (Machining, grinding, lapping etc)
4. 44
Types of Material Removal Operations:
Conventional:
•Milling
•Turning
•Shaping
• Grinding
Unconventional:
• Electro Chemical Machining
• Electro Discharge Machining
Abrasive processes:
• Grinding
• Deburring
Metal cutting is commonly used because:
• Casting and forging cannot give precisions shapes
• Its often easier to machine parts to get complicated shapes.
5. 55
Machining Processes
•Here specified shape is imparted to the work piece by removing
access of material in form of chips in conventional methods.
•This is done by interacting the work piece with tool.
•Tools may be SPCT, MPCT or abrasive materials.
Machining Process
SPCT
1. Turning
2. Boring
3. Shaping
4. Planning
MPCT
1. Milling
2. Drilling
3. Tapping
4. Reaming
5. Hobbing
6. Broaching
7. Sawing
Abrasive Operations
1. Grinding
2. Lapping
3. Honing
4. Super Finishing
6. 66
• Process where a stronger metal is used to cut a softer metal.
• One of the most popular and commonly used manufacturing
processes.
• Lathe has been used since mid-seventeenth century.
• Parts after heat treatment are usually distorted and hence need
machining.
• Imparts Accurate dimension, sharp corners.
• Imparts Desired texture - such as shiny finish, mirrored surface
etc.
• With modern machine it can be very economical.
Disadvantages:
• Higher cost of labor and tools.
• Scrap metal results.
• Longer cycle time.
7. 77
Oblique vs orthogonal cutting
Oblique Cutting:
• Cutting Edge of tool is inclined at an angle λs with normal to
cutting velocity vector.
• Chip generated flows on rake face of the tool at angle approx
equal to angle of inclination (λs) to the normal.
• Cutting edge extends beyond the work piece width on both
sides.
• Cutting forces act along all the three directions in x, y and z
axes.
• Suitable for efficient metal removal.
V
9. 99
Orthogonal Cutting:
• Cutting edge is perpendicular to direction of cutting velocity (V).
• λs = 0
• Cutting edge extends beyond the work piece width on both sides.
• Chip generated flows on rake face of the tool with chip velocity
perpendicular to cutting edge.
• Cutting forces act along x and z directions only.
• Unsuitable for efficient chip removal.
10. 1010
Mechanics of chip formation:
• Wedge shape tool is moved relative to work piece.
• Tool exerts pressure on work piece as it makes contact with the same causing
compression of metal near tool tip.
• Shear type plastic deformation within metal starts.
• Metal starts moving upwards along the top face of the tool.
• Tool advances and material ahead is sheared continuously along shear plane
(Primary shear zone).
• Tool surface along which chip moves upwards is called rake surface.
• Tool surface which is helps in avoiding rubbing with machined surface is called
rake surface.
11. 1111
Type of Chips
• Relative motion b/w tool & w/p causes material to compress & reach plastic
state.
• Formation of chips depends on work material and cutting operations.
• Chip moves upwards along the rake face of the tool.
• Three types of chips are formed.
1. Continuous chip. (Shearing phenomenon.)
2. Continuous chip with built up edge.
(Welding and rupture phenomenon)
3. Discontinuous chip. (High Strain in Brittle materials)
1.
2.
3.
12. 1212
Factors Type of chip
Continuous Continuous with BUE Discontinuous
Material Ductile Ductile Brittle
Tool:
Rake Angle Large Small Small
Cutting Edge Sharp Dull ----
Cutting Condition:
Speed High Low Low
Feed Low High High
Friction Low High ---
Cutting Fluid Efficient Poor Effective
Chip Thickness Small Large
Surface Finish: ---- Poor Better
13. 1313
Single Point Cutting Tool:
• A single-point tool is a cutting tool having one cutting part and one shank.
Tool Elements:
Shank: That part of the tool by which it is held.
Tool Axis: An imaginary straight line used for manufacturing and sharpening of the
tool and for holding the tool in use.
Generally, the tool axis is the center line of the tool shank.
Cutting Part or tool point: The functional part of the tool comprised of the chip
producing elements. The cutting edges, face, and flank are therefore elements of
the cutting part.
Base. A flat surface on the tool shank, parallel or perpendicular to the tool
reference plane useful for locating or orienting the tool in its manufacture,
sharpening and measurement. Not all tools have a clearly defined base.
Wedge. The portion of the cutting part enclosed between the face and the flank.
It can be associated with either the major or minor cutting edge.
14. 1414
Tool Surfaces:
•Rake Face (Ay): The surface or surfaces over which the chip flows.
•Chip Breaker: A modification of the face, to control or break the chip.
•Cutting Edge: That edge of the face which is intended to perform cutting.
Major/Side Cutting Edge: Edge which is intended to produce transient surface.
Minor/End Cutting Edge: Edge which is not intended to produce transient surface.
•Flank (Aa): The tool surface or surfaces over which the surface produced on the
work piece passes.
Major /Principal/Side Flank Surface: Flank Surface containing major cutting edge.
Minor/Auxiliary/End Flank Surface: Flank Surface Containing minor cutting edge.
•Corner or nose: The relatively small portion of the cutting edge at the junction of
the major and minor cutting edges
16. 1616
Reference planes in ASA system of tool designation:
• A plane parallel to ground containing tool shank is taken as
datum and is called base plane.
• Second reference plane is longitudinal plane and is along
longitudinal feed direction and perpendicular to base plane.
• Third reference plane is transverse plane and is
perpendicular to both the above planes.
19. 1919
American System of Tool
Specification
αb αs βe βs γe γs r
Back Rake Angle
Side Rake Angle
End Relief/Flank/clearance Angle
Side Relief/Flank/clearance Angle
End Cutting Angle
Side Cutting Angle
Nose Radius
20. 2020
Importance and selection of angles
Back Rake Angle (αb):
• It is the angle b/w rake face of the tool and line parallel to the base.
• Measured in a plane perpendicular to major (side) cutting edge.
• It is positive when major (side) cutting edge slopes downwards from the
point towards the shank and vice versa.
Side Rake Angle (αs):
• It is the angle b/w face of the tool and line parallel to the base.
• Measured in a plane perpendicular to the base and major (side) cutting
edge.
• It gives slope of the face of the tool from cutting edge.
• It is positive when slope is away from cutting edge and vice versa.
Importance:
• Larger the rake angle, smaller is the cutting angle and low cutting force
and power will be required.
• Decreasing cutting angle will leave less metal at point of tool to support
21. 2121
End Relief/Flank/clearance Angle (βe):
• Angle b/w portion of end (minor) flank immediately below minor (end)
cutting edge and a line perpendicular to the base of the tool.
• Measured at right angle to minor flank surface.
Side Relief/Flank/clearance Angle (βs):
• Angle b/w portion of side flank immediately below major (side) cutting
edge and a line perpendicular to the base of the tool.
• Measured at right angle to Major (side) flank.
Importance:
• Provided to avoid the rubbing of work piece and the tool during cutting.
• Flank of the tool clears the work piece surface and there is no rubbing
action b/w the two.
• Higher the relief angle, better will be the penetration and cut made by
the tool on work piece thus less cutting force and power required and lower
will be the flank face wear.
• But large rake angles weaken the cutting edge and heat dissipation is also
poor.
22. 2222
End Cutting Angle (γe):
• Angle b/w minor (end) cutting edge and line normal to tool shank.
Importance:
• Provides clearance or relief to trailing end of the cutting edge to prevent rubbing
b/w machined surface and trailing (non cutting) part of the tool.
Side Cutting Angle or Lead Angle (γs):
• Angle b/w major (side) cutting edge and side of the tool shank.
Importance:
• Provides interface as the tool enters the work material.
• This angle affects tool life and surface finish.
Nose Radius (r):
• For long tool life and surface finish.
23. 2323
Left and Right hand Cutting Tool:
•In a right cut tool side (major or primary) cutting edge is on
the side of the thumb when right hand is placed on the tool
with palm downward and fingers pointing towards the tool
nose.
•Such tool cuts when fed from right to left.
•In a left cut tool side (major or primary) cutting edge is on
the thumb side when left hand is placed on the tool with palm
downward and fingers pointing towards the tool nose.
• Such tool cuts when fed from left to right.
24. 2424
Measurement of Shear Angle (Φ)
• Shear Angle Φis defined as the angle made by shear plane with direction of tool
travel.
• Cutting Ratio or Chip thickness ratio or chip compression factor:
• Cutting ratio (r) is defined as the uncut chip thickness (t0) to chip thickness
after metal is cut (tc).
r = t0/tc
• Chip reduction factor (ζ) is the reciprocal of Cutting ratio.
ζ = 1/r = tc/t0
A
B
26. 2626
tanΦ = r*cosα/(1-r*sin α)
Now,
AB = to/sinΦ = tc/cos(Φ-α)
i.e. r = sinΦ / (cosΦcosα + sinΦsinα)
⇒ r*(cosΦcosα + sinΦsinα) = sinΦ
⇒ tanΦ = r*cosα/(1-r*sin α)
• This is a relationship between rake angle and shear angle.
27. 2727
•Now if the length of cut ‘lo’ is known, then as per continuity
equation:
ρlobt = ρlcbtc
Where,
• ρ is the density of the material and material is assumed to be
incompressible.
• lc is the length of the chip.
lc/lo = to/tc = r
• Thus relation b/w rake angle and shear angle can be
redefined.
28. 2828
Cutting forces:
Forces in cutting are to be calculated to:
• Ensure that the machine used can withstand such forces.
•To help minimize wear on tools and reduce power consumption.
Forces across shear plane:
Fs: Shear Force
Fn: Force normal to shear plane
α: positive tool rake angle.
Φ: Shear angle
λ: Friction angle.
Force at chip tool interface:
F: Friction Force
N: Normal Tool Force
Other Forces:
Fc: Cutting Force
Ft: Thrust Force
R: Resultant Force
μ: F/N = tan λ
Force Triangles
29. 2929
• Shear Force ‘Fs’ is resistance to shear of metal.
• Normal Force ‘Fn’ is the force that w/p provides for backing up.
• Fs and Fn are at right angle to each other.
• R’ is the resultant of Fs and Fn and equal and opposite to R which is the resultant
of F and N. Thus R’ and R can be used interchangeably.
• Normal Tool Force ‘N’ acts at tool chip interface and is provided by the tool.
• Frictional Force ‘F’ is the frictional resistance of the tool acting on chip.
• All these forces can be represented with a circle called Merchant Force Circle.
• On this circle force triangles are superimposed.
• R or R’ forms the diameter of this circle.
Merchant Force Circle
• Orthogonal components of R, cutting
force Fc (horizontal) and thrust force Ft
(vertical) can be measure with the help of
dynamometer.
• Power consumed during cutting ‘E’ is:
E = Fc*V
• Where V is cutting speed.
• Now:
VV
F = Fc*Sinα + Ft*Cosα
N = Fc*Cosα – Ft*Sinα
And
Fs = Fc*CosΦ – Ft*SinΦ
Fn = Fc*SinΦ – Ft*CosΦ
V
30. 3030
Now,
Shear Plane Area ‘As’ is
As = bto/sinΦ
And average stresses on shear plane area are:
Τs = Fs/As
σs = Fn/As
Also from Merchant Force Circle:
Also;
R = Fc*sec(λ-α)
Thus, Fs = Fc*sec(λ-α)*Cos(Φ+λ-α)
Since, Τs = Fs*SinΦ/bto
Thus, Τs = Fc*sec(λ-α)*Cos(Φ+λ-α)*SinΦ/bto
Now ‘α’ for a tool is constant and assuming that ‘λ’ is independent of ‘Φ’, and for
Maximum shear stress:
dΤs/dΦ = 0
Cos(Φ+λ-α)*CosΦ - Sin(Φ+λ-α)*SinΦ
Fs = R*Cos(Φ+λ-α)
and
Fc = R*Cos(λ-α)
31. 31
Now,
Cutting Power Pc:
Pc = Fc*V
V = ΠDN/(1000*60) in m/s
Thus,
Pc = Fc*V/1000 in Kw
tan(Φ+λ-α) = cotΦ = tan(900
-Φ)
• Thus on having high value of shear angle for a tool, value of friction angle reduces
• Thus low friction b/w tool and chip occurs and thus tool life increases and cutting
force required decreases.
Assumptions made by Merchant in making shear angle prediction:
• The work material behaves like an ideal plastic.
• The theory involves the minimum energy principle.
• As, Τs and λ are assumed to be constant and independent of Φ.
Φ = 450
+ α/2 – λ/2