cutting tool tech...... ammar

8/2/2019 Cutting Tool Tech...... Ammar

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TERM PAPERTOPIC: CUTTING TOOL TECHNOLOGY

SUBMITTED BY:

NAME- AMMAR BASHIRROLL NO.- A01

SECTIONMIR20

REG. NO.-11100132

SUBMITTED TO:

MR.

ABISHEK ABROL


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Acknowledgement

First of all, I would like to thank my god, for giving methe strength and health to do this project work until itdone Not forgotten to my family for providing

everything, such as money, to buy anything that are

related to this project work and their advise, which isthe most needed for this project. Internet, books,computers and all that as my source to complete this

project. They also supported me and encouraged me tocomplete this task so that I will not procrastinate indoing it.

Then I would like to thank my teacher, for guiding meand my friends throughout this project. We had somedifficulties in doing this task, but he taught us patiently

until we knew what to do. He tried and triedto teach us until we understand what we supposed todo with the project work.

Last but not least, my friends who were supporting to

me for this project with me and sharing our ideas. Theywere helpful that when we combined and discussed

together, we had this task done.
http://wiki.answers.com/Q/Sample_of_an_acknowledgementhttp://wiki.answers.com/Q/Sample_of_an_acknowledgementhttp://wiki.answers.com/Q/Sample_of_an_acknowledgementhttp://wiki.answers.com/Q/Sample_of_an_acknowledgement


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INTRODUCTION:

All machining operations are accomplished using cutting tools .

Cutting tool technology has two principal aspects: tool material and

tool geometry.

The first is concerned with developing tool materials that can

withstand the forces, temperatures and wearing action in the

machining operation.

The second deals with optimizing the geometry of the cutting tool for

the tool material and for a given operation.


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History:

The history of saw tools is a well-known one due to the fact that

we have been left a historical record in cave paintings, carvings and

the occasional tool that was buried, either by mistake or with ritual

burials. So we can see what tools the ancient people used and in

many cases the tools we use for sawing today haven't changed thatmuch. The ancient Egyptians left excellent carvings in stone and

paintings on their tombs that they built and even had themselves

buried with tools such as axes, saws and chisels thousands of years

ago. Going back even further into history reveals the use of saw

tools, even as far back as the early caveman who would use flint

rock, shaped into a cutting tool. Before modern times, that is, beforethe discovery of iron, most tools used wood in some way when

creating a tool for sawing. Wood would be used as a handle to hold

the cutting implement. Cavemen would use a wooden handle with

the flint stone strapped to the wood by animal guts or thin strips of

vegetation. Even today a wooden handle is still a common method of

creating a handle for a saw tool.

The cutting edge of a saw has moved on from the stone flints used in

ancient times through the use of copper and bronze in the early days

of the Egyptians. When copper and eventually bronze was

discovered the designs and uses of cutting tools changed to allow for

more complex designs. Knives and metal serrated edges began to be

used for cutting at a faster rate. The great change in cutting tools like


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saw tools, came about with the discovery of iron and eventually steel

combined with the power of steam as a source of power, tools could

suddenly be mass produced and the cutting blades made sharper and

stronger.


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Description:

In the context ofmachining , a cutting tool (or cutter) is any tool that

is used to remove material from the workpiece by means of shear

deformation. Cutting may be accomplished by single-point or

multipoint tools. Single-point tools are used in turning, shaping,

plainning and similar operations, and remove material by means of

one cutting edge. Milling and drilling tools are often multipoint

tools. Grinding tools are also multipoint tools. Each grain of abrasive

functions as a microscopic single-point cutting edge (although of

high negative rake angle), and shears a tiny chip.

Cutting tools must be made of a material harder than the material

which is to be cut, and the tool must be able to withstand the heat

generated in the metal-cutting process. Also, the tool must have aspecific geometry, with clearance angles designed so that the cutting

edge can contact the workpiece without the rest of the tool dragging

on the workpiece surface. The angle of the cutting face is also

important, as is the flute width, number of flutes or teeth, and

margin size. In order to have a long working life, all of the above

must be optimized, plus the speeds and feeds at which the tool is run.
http://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Rake_anglehttp://en.wikipedia.org/wiki/Hardnesshttp://en.wikipedia.org/wiki/Speeds_and_feedshttp://en.wikipedia.org/wiki/Speeds_and_feedshttp://en.wikipedia.org/wiki/Hardnesshttp://en.wikipedia.org/wiki/Rake_anglehttp://en.wikipedia.org/wiki/Machining


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Materials

Cutting tools are made using a variety of materials and theselection of a cutting tool material depends on a variety offactors.

To produce quality parts, a cutting tool must have three

characteristics:

Hardness hardness and strength at high temperatures.

Toughness toughness, so that tools dont chip or fracture.

Wear resistance having acceptable tool life beforeneeding to be replaced.

Cutting tool materials can be divided into two main categories:stable and unstable.

Unstable materials (usually steels) are substances that start ata relatively low hardness point and are then heat treated topromote the growth of hard particles (usually carbides) insidethe original matrix, which increases the overall hardness of thematerial at the expense of some its original toughness. Sinceheat is the mechanism to alter the structure of the substanceand at the same time the cutting action produces a lot of heat,such substances is inherently unstable under machining

conditions.

Stable materials (usually tungsten carbide) are substances thatremain relatively stable under the heat produced by mostmachining conditions, as they don't attain their hardnessthrough heat. They wear down due to abrasion, but generallydon't change their properties much during use.

Most stable materials are hard enough to break before flexing,

which makes them very fragile. To avoid chipping at the cuttingedge, most tools made of such materials are finished with a
http://en.wikipedia.org/wiki/Toughnesshttp://en.wikipedia.org/wiki/Wearhttp://en.wikipedia.org/wiki/Wearhttp://en.wikipedia.org/wiki/Toughness


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sightly blunt edge, which results in higher cutting forces due toan increased shear area. Fragility combined with high cuttingforces results in most stable materials being unsuitable for usein anything but large, heavy and stiff machinery.

Unstable materials, being generally softer and thus tougher,generally can stand a bit of flexing without breaking, whichmakes them much more suitable for unfavorable machiningconditions, such as those encountered in hand tools and lightmachinery.

Tool material Properties

Carbon steel

Unstable. Very inexpensive. Extremely sensitive to

heat. Considered obsolete today although it is still

found in non-intensive applications such as hand

operated tools (e.g. reamers and taps). Hardness up

to about HRC 65. Sharp cutting edges possible.

High speed

steel(HSS)

Unstable. Inexpensive. Retains hardness at moderate

temperatures. The most common cutting tool

material used today. Used extensively on drill bits and

taps. Hardness up to about HRC 67. Sharp cutting

edges possible.

HSS cobalt

Unstable. Moderately expensive. The high cobalt

versions of high speed steel are very resistant to heat

and thus excellent for machining abrasive and/or

work hardening materials such as titanium and

stainless steel. Used extensively on milling cutters and

drill bits. Hardness up to about HRC 70. Sharp cutting
http://en.wikipedia.org/wiki/Carbon_steelhttp://en.wikipedia.org/wiki/Carbon_steelhttp://en.wikipedia.org/wiki/High_speed_steelhttp://en.wikipedia.org/wiki/High_speed_steelhttp://en.wikipedia.org/wiki/High_speed_steelhttp://en.wikipedia.org/wiki/High_speed_steelhttp://en.wikipedia.org/wiki/Carbon_steel


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edges possible.

Castcobalt

alloys

Stable. Expensive. Somewhat fragile. Despite its

stability it doesn't allow for high machining speed due

to low hardness. Not used much. Hardness up to

about HRC 65. Sharp cutting edges possible.

Cemented

carbide

Stable. Moderately expensive. The most common

material used in the industry today. It is offered in

several "grades" containing different proportions of

tungsten carbide and binder (usually cobalt). High

resistance to abrasion. High solubility in iron requires

the additions of tantalum and niobium carbides for

steel usage. Its main use is in turning tool bits

although it is very common in milling cutters and saw

blades. Hardness up to about HRC 90. Sharp edgesgenerally not recommended.

Ceramics

Stable. Moderately inexpensive. Chemically inert and

extremely resistant to heat, ceramics are usually

desirable in high speed applications, the only

drawback being their high fragility. Ceramics are

considered unpredictable under unfavorable

conditions. The most common ceramic materials are

based on alumina (aluminium oxide), silicon nitride

and silicon carbide. Used almost exclusively on

turning tool bits. Hardness up to about HRC 93. Sharp

cutting edges and positive rake angles are to be

avoided.
http://en.wikipedia.org/wiki/Cobalt_alloyhttp://en.wikipedia.org/wiki/Cobalt_alloyhttp://en.wikipedia.org/wiki/Cemented_carbidehttp://en.wikipedia.org/wiki/Cemented_carbidehttp://en.wikipedia.org/wiki/Cemented_carbidehttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Cemented_carbidehttp://en.wikipedia.org/wiki/Cemented_carbidehttp://en.wikipedia.org/wiki/Cobalt_alloyhttp://en.wikipedia.org/wiki/Cobalt_alloy


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Cermets

Stable. Moderately expensive. Another cemented

material based on titanium carbide (TiC). Binder is

usually nickel. It provides higher abrasion resistancecompared to tungsten carbide at the expense of

some toughness. It is far more chemically inert than it

too. Extremely high resistance to abrasion. Used

primarily on turning tool bits although research is

being carried on producing other cutting tools.

Hardness up to about HRC 93. Sharp edges generally

not recommended.

Cubic boronnitride(CBN)

Stable. Expensive. Being the second hardest

substance known, it is also the second most fragile. It

offers extremely high resistance to abrasion at the

expense of much toughness. It is generally used in a

machining process called "hard machining", whichinvolves running the tool or the part fast enough to

melt it before it touches the edge, softening it

considerably. Used almost exclusively on turning tool

bits. Hardness higher than HRC 95. Sharp edges

generally not recommended.

Diamond

Stable. Very Expensive. The hardest substance known

to date. Superior resistance to abrasion but also high

chemical affinity to iron which results in being

unsuitable for steel machining. It is used where

abrasive materials would wear anything else.

Extremely fragile. Used almost exclusively on turning

tool bits although it can be used as a coating on many
http://en.wikipedia.org/wiki/Cermethttp://en.wikipedia.org/wiki/Cermethttp://en.wikipedia.org/wiki/Cubic_boron_nitridehttp://en.wikipedia.org/wiki/Cubic_boron_nitridehttp://en.wikipedia.org/wiki/Diamondhttp://en.wikipedia.org/wiki/Diamondhttp://en.wikipedia.org/wiki/Diamondhttp://en.wikipedia.org/wiki/Cubic_boron_nitridehttp://en.wikipedia.org/wiki/Cubic_boron_nitridehttp://en.wikipedia.org/wiki/Cermet


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kinds of tools. Sharp edges generally not

recommended.

Hand tool

A hand tool is a device for performing work on a material or aphysical system using only hands. The hand tools can be

manually used employing force, or electrically powered, usingelectrical current.[

Virtually every type of tool can be a hand tool and many havealso been adapted as power tools, which get their motive powerfrom motors or engines rather than from human mechanicalaction.

Machine tool
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Lathe is an example of a machine toolA machine tool is a powered mechanical device, typically usedto fabricate metal components of machines by machining,which is the selective removal of metal. The term machinetoolis usually reserved for tools that used a power source otherthan human movement, but they can be powered by people ifappropriately set up. Many historians of technology considerthat the true machine tools were born when direct human

involvement was removed from the shaping or stampingprocess of the different kinds of tools. The earliest lathe withdirect mechanical control of the cutting tool was a screw-cuttinglathe dating to about 1483. This lathe "produced screw threadsout of wood and employed a true compound slide rest".

The first machine tools offered for sale (i.e. commerciallyavailable) were constructed by one Matthew Murray in Englandaround 1800.

Power tool

A power tool is a tool powered by an electric motor, an internalcombustion engine, a steam engine, compressed air, directburning of fuels and propellants, or even natural power sourceslike wind or moving water. Power tools are classified as either

stationary or portable, where portable means handheld. Theyare used in industry, in construction, and around the house fordriving, drilling, cutting, shaping, sanding, grinding, polishing,painting, and heating. Stationary power tools for metalworkingare usually calledmachine tools. The term machine toolis notusually applied to stationary power tools for woodworking,although such usage is occasionally heard, and in some cases,such as drill presses and bench grinders, exactly the same tool

is used for both woodworking and metalworking.
http://en.wikipedia.org/wiki/Lathehttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Matthew_Murrayhttp://en.wikipedia.org/wiki/Toolhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Machine_toolshttp://en.wikipedia.org/wiki/Machine_toolshttp://en.wikipedia.org/wiki/Machine_toolshttp://en.wikipedia.org/wiki/Drill#Drill_presshttp://en.wikipedia.org/wiki/Bench_grinderhttp://en.wikipedia.org/wiki/Bench_grinderhttp://en.wikipedia.org/wiki/Drill#Drill_presshttp://en.wikipedia.org/wiki/Machine_toolshttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Toolhttp://en.wikipedia.org/wiki/Matthew_Murrayhttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Lathe


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Stationary power tools are prized not only for their speed, butfor their accuracy. A table saw not only cuts faster than a handsaw, but the cuts are smoother, straighter and more squarethan even the most skilled man can do with a hand saw. Lathesproduce truly round objects that cannot be made in any otherway.

Common power tools include the drill, various types of saws,the router, the electric sander, and the lathe.

The term power tool is also used in a more general sense,meaning a technique for greatly simplifying a complex ordifficult task.

Examples::

Air compressor,shear, Angle,Bandsaw , ,Ceramic tilecutter tile saw,ChainsaBelt sander,Biscuit joinerw,Circularsaw,Concrete saw,Cold saw,Crusher,Diamond blade ,Discsander,Drill

Tool geometry:

Cutting tool has one or more sharp cutting edges depending

upon the machining operation. There are two basic category in

cutting tool that we generally categorize.

Single point cutting tool: A single-point cutting tool has one cutting

edges and is used for operations such as turning.
http://en.wikipedia.org/wiki/Drillhttp://en.wikipedia.org/wiki/Sawhttp://en.wikipedia.org/wiki/Wood_routerhttp://en.wikipedia.org/wiki/Electrichttp://en.wikipedia.org/wiki/Sanderhttp://en.wikipedia.org/wiki/Lathe_(tool)http://en.wikipedia.org/wiki/Air_compressorhttp://en.wikipedia.org/wiki/Ceramic_tile_cutterhttp://en.wikipedia.org/wiki/Ceramic_tile_cutterhttp://en.wikipedia.org/wiki/Chainsawhttp://en.wikipedia.org/wiki/Circular_sawhttp://en.wikipedia.org/wiki/Circular_sawhttp://en.wikipedia.org/wiki/Concrete_sawhttp://en.wikipedia.org/wiki/Cold_sawhttp://en.wikipedia.org/wiki/Crusherhttp://en.wikipedia.org/wiki/Disc_sanderhttp://en.wikipedia.org/wiki/Disc_sanderhttp://en.wikipedia.org/wiki/Drillhttp://en.wikipedia.org/wiki/Drillhttp://en.wikipedia.org/wiki/Disc_sanderhttp://en.wikipedia.org/wiki/Disc_sanderhttp://en.wikipedia.org/wiki/Crusherhttp://en.wikipedia.org/wiki/Cold_sawhttp://en.wikipedia.org/wiki/Concrete_sawhttp://en.wikipedia.org/wiki/Circular_sawhttp://en.wikipedia.org/wiki/Circular_sawhttp://en.wikipedia.org/wiki/Chainsawhttp://en.wikipedia.org/wiki/Chainsawhttp://en.wikipedia.org/wiki/Chainsawhttp://en.wikipedia.org/wiki/Ceramic_tile_cutterhttp://en.wikipedia.org/wiki/Ceramic_tile_cutterhttp://en.wikipedia.org/wiki/Air_compressorhttp://en.wikipedia.org/wiki/Lathe_(tool)http://en.wikipedia.org/wiki/Sanderhttp://en.wikipedia.org/wiki/Electrichttp://en.wikipedia.org/wiki/Wood_routerhttp://en.wikipedia.org/wiki/Sawhttp://en.wikipedia.org/wiki/Drill


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Multiple cutting edges tool: Most multiple cutting edges tools are

used in machining operation in which the tool is rotated .

Turning:

Turning is the process whereby a single point cutting tool isparallel to the surface. It can be done manually, in a traditionalform of lathe, which frequently requires continuous supervisionby the operator, or by using a computer controlled andautomated lathe which does not. This type of machine tool isreferred to as having computer numerical control, better knownas CNC.And is commonly used with many other typesof machine tool besides the lathe.

When turning, a piece of material (wood, metal, plastic, orstone) is rotated and a cutting tool is traversed along 2 axes ofmotion to produce precise diameters and depths. Turning canbe either on the outside of the cylinder or on the inside (alsoknown as boring) to produce tubular components to variousgeometries. Although now quite rare, early lathes could evenbe used to produce complex geometric figures, eventhe platonic solids; although until the advent of CNC it had

become unusual to use one for this purpose for the last three
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quarters of the twentieth century. It is said that the lathe is theonly machine tool that can reproduce itself.

The turning processes are typically carried out on a lathe,

considered to be the oldest machine tools, and can be of fourdifferent types such as straight turning, taperturning, profilingor externalgrooving. Those types of turningprocesses can produce various shapes of materials suchas straight, conical,curved, or groovedworkpiece. In general,turning uses simple single-point cuttingtools. Each group ofworkpiece materials has an optimum set of tools angles whichhave been developed through the years.

The bits of waste metal from turning operations are known aschips (North America), or swarf (Britain). In some areas theymay be known as turnings.
http://en.wikipedia.org/wiki/Swarfhttp://en.wikipedia.org/wiki/Swarf


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Drilling:

Drilling is the most common machining process whereby theoperation involves makinground holes in metallic andnonmetallic materials. Approximately 75% of all metal-cuttingprocess is of the drilling operation.Drills usually have a high length to diameter ratio that iscapable of producing deep hole,however due to its flexibility,

necessary precaution need to be taken to maintainaccuracyand prevent drill from breaking.Drilled holes can be either through holes or blind holes . Athrough holes is made when a drill exits the opposite side of thework; in blind hole the drill does notexit the workpiece .

During the operation, chips that are produced within theworkpiece must exit through theflutes to the outside of the tool.

As the chip is formed and extracted towards the surface,it will


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generate friction. Friction subsequently heat is also generatedwhen the drill bittouch the workpiece during the holemakingprocess.Therefore, chip disposal and cuttingfluids are amongthe most important elements need to be consider during thisprocess.

Milling is a machining operation in which a workpiece is fed past a

rotating cylindrical tool

with multiple cutting edges. The axis of rotation of the tool is

perpendicular to the feed direction. The

tool is called the milling cutter and the cutting edges are called

teeth. Mostly plane surfaces are

created through milling. Its an interrupted cutting operation; the

teeth of milling cutter enter and exit

workpiece during each revolution. So, the tool material and cutter

geometry must be chosen carefully .

There are two basic types of milling operations :


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1.Peripheral milling- Also called plain milling in which the axis of

tool is parallel to the surface being machined and the

operation is performed by cutting edges on the outside

periphery of the cutter .

2.Face millingIn face milling ,the axis of cutter is perpendicular to

the surface being milled, and the machining is performed by cutting

edges on both end and outside periphery of the cutter.


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References-

1.Textbook Mikell P. Groover

2.Wikipedia

3.www.google.com

cutting tool tech...... ammar

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