machine tools laboratory (14ame15)

MT LAB MECHANICAL / IVSEM

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MACHINE TOOLS LABORATORY

(14AME15)

(For II B.Tech Mechanical Engineering)

DEPARTMENT OF MECHANICAL ENGINEERINGDEPARTMENT OF MECHANICAL ENGINEERINGDEPARTMENT OF MECHANICAL ENGINEERINGDEPARTMENT OF MECHANICAL ENGINEERING

SRI VENKATESWARA COLLEGE OF ENGINEERING &

TECHNOLOGY

R.V.S NAGAR, CHITTOOR-517127


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CONTENTS

S.No.

TITLE

PAGE NO.

1 GENARAL INFORMATION 3

2 GENERAL INSTRUCTIONS 4

3 MACHINING PROCESSES 6

4 LIST OF EXPERIMENTS 8

• LATHE MACHINE OPERATIONS

• SHAPING & SLOTING

• DRILLING OPERATIONS

• MILLING OPERATIONS

5 APPENDIX 25


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GENERAL INFORMATION

This laboratory is aimed at providing an introduction to the Know-how of common

processes used in industries for manufacturing parts by removal of material in a controlled

manner. Auxiliary methods for machining to desired accuracy is covered. The emphasis

throughout the laboratory course will be on understanding the basic features of the processes

rather than details of constructions of machine, or common practices in manufacturing or

acquiring skill in the operation of machines. Evidently, acquaintance with the machine is

desirable and the laboratory sessions will provide adequate opportunity for this.


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GENERAL INSTRUCTIONS AND SAFETY RULES

1. Students should wear the uniform and closed foot wear. Students inappropriately dressed

for lab, at the instructor’s discretion, be denied access).

2. When you handle chemicals wear eye protection (chemical splash goggles or full face

shield).

3. When you work with furnaces for heat treatment procedures or other thermally activated

equipment you should use special gloves to protect your hands.

4. To protect clothing from chemical damage or other dirt, wear a lab apron or lab coat.

Long hair should be tied back to keep it from coming into contact with lab chemicals or

flames.

5. In case of injury (cut, burn, fire etc.) notify the instructor immediately.

6. In case of a fire or imminently dangerous situation, notify everyone who may be affected

immediately; be sure the lab instructor is also notified.

7. If chemicals splash into someone's eyes act quickly and get them into the eye wash

station, do not wait for the instructor.

8. In case of a serious cut, stop blood flow using direct pressure using a clean towel, notify

the lab instructor immediately.

9. Eating, drinking and smoking are prohibited in the laboratory at all times.

10. Never work in the laboratory without proper supervision by an instructor.

11. Never carry out unauthorized experiments. Come to the laboratory prepared. If you are

unsure about what to do, please ask the instructor.

12. Except the scientific calculator, any other electronic devices are not permitted to use

inside the Laboratory.

13. Any damage to any of the equipment/instrument/machine caused due to carelessness, the

cost will be fully recovered from the individual (or) group of students.


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MACHINING PROCESSES

MACHINING PROCESSES Machining is one of the processes of manufacturing in

which the specified shape to the work piece is imparted by removing surplus material.

Conventionally this surplus material from the work piece is removed in the form of chips by

interacting the work piece with an appropriate tool. This mechanical generation of chips can be

carried out by single point or multi point tools or by abrasive operations these are summarized

below:

Machining Processes

Single point tool operations Multi-point tool operations Abrasive operations

1. Turning 1. Milling 1. Grinding

2. Boring 2.Drilling 2. Lapping

3. Shaping 3. Tapping 3. Honing

4. Planing 4. Reaming 4. Super-finishing

5. Hobbing

6. Broaching

7. Sawing

The process of chip formation in metal cutting is affected by relative motion between the

tool and the work piece achieved with the aid of a device called machine tool. This relative

motion can be obtained by a combination of rotary and translatory movements of either the tool

or the workpiece or both. The kind of surface that is produced by the operation depends on the

shape of the tool and the path it traverses through the materials. When the workpiece is rotated

about an axis and the tool is traversed in a definite path relative to the axis, a surface of

revolution is generated. When the tool path is parallel to the axis, the surface generated is a

cylinder as in straight turning (Fig.1.) or boring (Fig.2.) operations. Similarly, planes may be

generated by a series of straight cuts without rotating the work piece as in shaping and planning

operations (Fig.3). In shaping the tool is reciprocating and the work piece is moved crosswise at

the end of each stroke. Planning is done by reciprocating the work piece and crosswise

movement is provided to the tool. Surface may be machined by the tools having a number of

cutting edges that can cut successively through the work piece materials. In plane milling, the

cutter revolves and moves over the work piece as shown (Fig.4). The axis of the cutter is parallel

to the surface generated. Similarly in drilling, the drill may turn and be fed into the work piece of

the workpiece may revolve while the drill is fed into it (Fig.5). The machine tools, in general,

provide two kinds of relative motions. The primary motion is responsible for the cutting action

and absorbs most of the power required to perform the machining action. The secondary motion

of the feed motion may proceed in steps or continuously and absorbs only a fraction of the total

power required for machining. When the secondary motion is added to the primary motion,

machine surfaces of desired geometric characteristics are produced. . Consider a situation where

both the cutting motions as well as the feed motion (provided at the end of each stroke) are

rectilinear but perpendicular to each other. Here the machined surface produced is a plane. The


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line generated by the primary motion (cutting motion) is called the generatrix, while the line

representing the secondary motion (feed motion) is called the directrix (Fig. 6a). Depending

upon the shapes of the generatrix and the directrix and their relative orientation various

geometries can be produced on the workpiece. Consider another case when the generatrix is a

circle and the directrix is a line perpendicular to the plane of the generatrix. It is clear that in this

situation the surface produced will be a cylinder (Fig. 6b). A tapered surface can be produced by

merely changing the angle that the directrix makes with the plane of the generatrix. When the

directrix is in the plane of the circular generatrix (Fig. 6c), lines are generated which results in a

plain surface when a number of generatrices and directrices are placed side by side in the

direction perpendicular to the plane of the generatrix. In actual practice, the cutting is performed

by cutting edge and not a point. Thus, a series of generatrix directrix combinations are involved

and the relative motion produces a surface rather than a line. Basically there are two methods of

producing new surfaces, the tracing method and the generation method. In the tracing method the

surface is obtained by direct tracing of the generatrices and when the surface produced is the

envelope of the generatrics the process is known as generation. Figs. 6(a) & 6{b), the plane and

the cylindrical surfaces are obtained by direct tracing, while in Fig. 6(c) the final surface

geometry is the envelope of the generatrices.

Fig. 1 Straight turning Fig. 2 Straight boring

Fig. 3 Shaping and planning Fig. 4 planning


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Fig. 5 Drilling

Fig.6 Concept of generatrix and directrix. (a) Rectilinear generatrix and directrix.

(b) Directrix perpendicular to the plane of generatrix.

(c) Directrix in the plane of generatrix.


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LIST OF EXPERIMENTS

S.No.

NAME OF THE EXPERIMENT

PAGE No.

DATE OF

Exp.

FACULTY

SIGNATURE

LATHE MACHINE OPERATIONS

1

STEP TURNING AND TAPER TURNING

2

KNURLING AND THREAD CUTTING

SHAPING & SLOTING

3

CONVERSION OF CIRCULAR ROD

INTO SQUARE ROD

4

SLOT MAKING

DRILLING OPERATIONS

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DRILLING AND TAPPING

MILLING

6

SPUR GEAR CUTTING


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Experiment No. Date:

STEP TURNING AND TAPER TURNING

AIM

To perform various lathe operations such as facing, plain turning, step turning and taper

turning on a given material made of Mild steel.

MATERIAL REQUIRED

A mild steel bar of 25 mm diameter and 100 mm length.

TOOLS AND EQUIPMENT USED

H.S.S. single point cutting tool,

Chuck key,

Tool post key,

Outside caliper,

Steel rule.

SEQUENCE OF OPERATIONS

1. Facing H.S.S Single Point tool

2. Rough turning H.S.S Single Point tool

3. Finish turning H.S.S Single Point tool

4. Step turning H.S.S Single Point tool

5. Taper turning H.S.S Single Point tool

PROCEDURE

• The work piece is fixed in a 3 – jaw chuck with sufficient overhang.

• Adjust the machine to run the job to a required cutting speed.

• Fix the cutting tool in the tool post and centering operation is performed so that the axis

of the job coincides with the lathe axis.

• Give the feed and depth of cut to the cutting tool.

• Facing operation is performed from the center of the job towards outwards or from the

circumference towards the center.

• Plain turning operation is performed until the diameter of the work piece reduces to 23

mm.

• Check the dimensions by using vernier calipers.

• Perform the plain turning operation on the same work piece for the required length in

order to reduce the diameter to 18 mm so as to get the step turning.

• Using a V – cutting tool grooving operation is performed according to the given

dimensions and finishes the groove using parting tool.


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• Swivel the compound slide to the required angle and perform taper turning operation by

rotating the compound slide wheel.

• The angle can be measured by using the formula Tanα = (D – d) / 2L.

• Finally check the dimensions by using vernier calipers.

PRECAUTIONS

• The work piece should be held rigidly in the chuck before operating the machine.

• Tool should be properly ground, fixed at correct height and properly secured, and work

also be firmly secured.

• Before operating the machine see whether the job and tool is firmly secured in devices or

not.

• Optimum machining conditions should be maintained.

• Chips should not be allowed to wound around a revolving job and cleared as often as

possible

• Apply cutting fluids to the tool and work piece properly.

MODEL CALCULATIONS

The amount by which the compound rest has to be swivel is estimated using the taper

angle. Taper angle is calculated as follows.

Taper angle (α) = Tan-1(� – �)

��

Where,

D = Diameter of bigger end, mm

d = Diameter of smaller end, mm

L = Length of taper, mm


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SKECTH

RESULT:


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KURNLING AND THREAD CUTTING

AIM

To perform Thread cutting and Knurling operation on the given work piece.

MATERIAL REQUIRED

Mild Steel rod of 25 mm diameter and 100 mm long

TOOLS REQUIRED

Vernier calipers,

Steel rule,

Spanner,

Shuck spanner

H.S.S. single point cutting tool

PROCEDURE

• The work piece is fixed in a 3 – jaw chuck with sufficient overhang.

• Adjust the machine to run the job to required cutting speed.

• Fix the cutting tool in the tool post and centering operation is performed so that the axis

of the job coincides with the lathe axis.

• Facing is performed by giving longitudinal depth of cut and cross feed.

• Perform plain turning operation until the diameter of the work piece reduced to 20mm.

• Using V-cutting tool and parting off tool perform grooving operation to the required

dimensions.

• Reduce speed of the spindle by engaging back gear and use Tumbler feed reversing

mechanism to transmit power through the lead screw.

• And calculate the change gears for the required pitch to be made on the work piece.

• Using half nut mechanism perform thread cutting operation(right hand threading)

according to the given dimensions and continues it until required depth of cut is obtained.

• At the same speed knurling operation is performed using knurling tool.

• For every operation check the dimensions using vernier calipers.


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PRECAUTIONS

• Before starting the spindle by power, lathe spindle should be revolved by one revolution

by hand to make it sure that no fouling is there.

• Tool should be properly ground, fixed at correct height and properly secured, and work

also be firmly secured.

• Chips should not be allowed to wind around a revolving job and cleared as often as

possible.

• Before operating threading operation, V-tool should be properly ground to the required

helix angle.

• Apply cutting fluids to the tool and work piece property.

• No attempt should be made to clean the revolving job with cotton waste.

• On hearing unusual noise, machine should be stopped.

SKECTH

RESULT


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DRILLING AND TAPPINNIG

AIM

To perform drilling, and tapping operations on the given M.S Flat work piece.

APPARATUS

1. Drilling Machine with standard accessories

2. Work piece

MATERIAL

Mild Steel flat plate 50 mm × 50 mm ×10 mm

PROCEDURE

• The given work piece is first filed to get required length, breadth and thickness wet chalk is

applied on four sides and with the scriber lines are drawn to get center hole at required location.

• The centers are punched with a Punch and hammer.

• The work piece is fixed firmly in the vice of the Drilling Machine

• 3/8” drill bit is fixed firmly in the chuck and drilling is performed giving uniform depths.

• The drill bit is removed from the drill chuck and is replaced by a reamer.

• The reaming operation is performed on the hole which has been previously drilled.

• The work is removed from the vice for performing tapping operation.

• The job is fixed firmly in a bench vice.

• Tap is fixed in the tap handle and pressure applied on the taps to obtain internal thread.

PRECAUTIONS

• Reaper should be free from moisture

• Marking is done without parallax error

• Care should be taken while cutting and drilling.

• While performing drilling and tapping operations lubricant should be used to minimize the

friction.


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SKECTH

RESULT


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CONVERSION OF CIRCULAR ROD INTO SQUARE ROD

AIM

To perform shaping operation of given mild steel rod.

MATERIAL REQUIRED

A Mild steel rod of 25 mm diameter and 100 mm length.

MACHINNE REQUIRED

Shaper machine

CUTTING TOOLS

H.S.S.Tool bit of the required slot size.


1 .Fix the specimen in the machine vice

2 .By giving the required feed and depth of cut, the required cut is being made progressively.

PROCEDURE

• Dimension of the work piece is measured and made to the required dimensions.

• fix the job in vice and adjust the tool in the tool head.

• Start the machine during forward stroke only remove the material and during the return stroke is

idle.

• 4. Do the operation to get one side completely flat then repeat the process on four sides of the

work piece.

• Rotate the job after completion of each side is flat.

• Then check the flat ness by using slip gauges. To get the required component.

PRECAUTION:

� Choose proper feed and depth of cut.

� Feed should be controlle4d to avoid to any damage to the cutting tool.

� Fix the work piece is properly into the vice.

� During cutting to supply coolant in between to the work piece and tool.

� Adjust the stroke length properly.


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RESULT


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SLOT MAKING

AIM

To make a slot on the given work piece.

MATERIALS REQUIRED

M.S Round Block, Wooden Block

MACHINE REQUIRED

Slotting machine

MEASURING INSTRUMENTS

Vernier calipers slip gauges.

CUTTING TOOLS

H.S.S.Tool bit of the required slot size.


• Fix the specimen in the three-jaw chuck of the slotting machine

• By giving the required feed and depth of cut, the required slot is being made

progressively

PROCEDURE

� Fix the work piece in the head stock chuck firmly

� Turning tool is fixed in the tool post and centering is to be done

� Turn the job to get a diameter of required length

� Facing is to be done on one side of the job

� Drill bit of 8 mm diameter is fixed on tail stock and centering of workPiece is to be done

by feeding through tail stock.

� Drill bit of 25 mm diameter is fixed in tail stock

� Drill through a hole of 25 mm diameter in the work piece feeding the tailstock.


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� Boring tool is the fixed on tail stock to perform boring operation to get a hole of required

diameter

� Fit the job in reverse position in the chuck

� Facing of other side of the work piece is to be done to get the required length of the job

� Drilled work piece is fixed on slotting machine.

� A slot of required depth is made

� Slowly cross and longitudinal feed is given to obtain slots as per requirement.

PRECAUTIONS

� Choose proper feed and depth of cut.

� Feed should be controlled to avoid any damage to the cutting tool

� Lock the index table before starting the operation.

� Care has to be taken so as to maintain the right feed of the material.

� Work-wheel interface zone is to be flooded with coolant

SKECTH


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RESULT


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SPUR GEAR CUTTING

AIM

To perform plane milling operation on the given specimen (mild steel)

MATERIALS REQUIRED

Mild steel specimen.

MACHINE REQUIRED

Milling machine

MEASURING INSTRUMENTS

Vernier calipers

CUTTING TOOLS

Plane (face) milling cutter

MARKING TOOLS

Steel rule, scriber

a. Work holding fixtures: work piece supporting fixtures

b. Miscellaneous tools: Hammer, brush, Allen keys


i. Measuring of specimen

ii. Fixing of specimen in the milling m/c.

iii. Giving the correct depth and automatic feed cut thespecimen

iv. Check the specimen with Vernier caliper at the end.


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PROCEDURE

� Select and cut a piece of stock to make the blank. Allow at least 1/8 inch excess material

on the diameter and thickness of the blank for cleanup cuts.

� Mount the stock in a chuck on a lathe. At the center of the blank, face an area slightly

larger the than the diameter of the required bore.

� Drill and bore to the required size (within tolerance). Remove the blank from the lathe

and press it on a mandrel.

� Set up the mandrel on the milling machine between the centers of the index head and the

footstock. Dial in within tolerance.

� Select a involute gear cutter and mount and center it. Set the index head to index 24

divisions. Start the milling machine spindle and move the table up until the cutter just

touches the gear blank.

� Set the micrometer collar on the vertical feed handwheel to zero, then hand feed the table

up toward the cutter slightly less than the whole depth of the tooth. Cut one tooth groove.

� Then index the work piece for one division and take another cut. Check the tooth

dimensions with a vernier gear tooth caliper as described previously.

� Make the required adjustments to provide an accurately “sized” tooth. Continue indexing

and cutting until the teeth are cut around the circumference of the work piece.

� The top surface of the job is milled in stages; giving finish cuts towards the end such that,

the height of the job is exactly 40 mm.

� The burrs if any along the edges are removed with the help of the flat file.

MODEL CALCULATIONS

Indexing Ratio =

Where, n = No. of slots on the periphery of the indexing plate.

N = Required number of divisions

Direct Indexing

Indexing Ratio = ��

Where N= required number of divisions


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Simple Indexing

Number of holes to move = ��

Where N= required number of divisions

Standard Brown and Sharp Index Plates

No.1: 15, 16, 17, 18, 19, 20

No.2: 21, 23, 27, 31, 33

No.3: 37, 39, 41, 43, 47, 49

Example: It is required to divide the periphery of a job into 60 divisions.

Crank Movement (Indexing Ratio) according to simple Indexing = 40/60 = 2/3

�

=

�

×

�

� =

��

��

The crank has to move 12 holes on 18 holes circle.

PRECAUTIONS

� The milling machine must be stopped before setting up or removing a work piece, cutter

or other accessory

� Never stop the feeding of job when the cutting operation is going on, otherwise the tool

will cut deeper at the point where feed is stopped.

� All the chips should be removed from the cutter. A wiping cloth should be placed on the

cutter to protect the hands. The cutter should be rotated in the clockwise direction only

for right handed tools.

� The work piece and cutter should be kept as cool as possible (i.e. coolant should be used

where necessary to minimize heat absorption).

� The table surface should be protected with a wiping cloth.

� Tool must be mounted as close to the machine spindle as possible.

MT LAB

RESULT

MECHANIC

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MECHANICAL / IVSEM


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APPENDIX

OULLINE OF VARIOUS MACHINE TOOLS

LATHE MACHINE

A lathe is a machine tool which rotates the work piece on its axis to perform various

operations such as cutting, sanding, knurling, drilling, or deformation with tools that are applied

to the work piece to create an object which has symmetry about an axis of rotation.

Lathes are used in woodturning, metalworking, metal spinning, and glass working.

Lathes can be used to shape pottery, the best-known design being the potter’s wheel. Most

suitably equipped metalworking lathes can also be used to produce most solids of revolution,

plane surfaces and screw threads or helices. Ornamental lathes can produce three-dimensional

solids of incredible complexity. The material can be held in place by either one or two centers, at

least one of which can be moved horizontally to accommodate varying material lengths. Other

work holding methods include clamping the work about the axis of rotation using a chuck to a

faceplate, using clamps or dogs.

MT LAB

SHAPER MACHINE

A shaper is a type of machine tool that uses linear relative motion between the

and a single-point cutting tool to machine a linear tool path. Its cut is

lathe, except that it is linear instead of helical. (Adding axes of

paths, as also done in helical planning.) A shaper is

the cutter riding a ram that moves above

piece moving beneath the cutter. The ram is mo

column; hydraulically actuated shapers also exist.

MECHANIC

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e of machine tool that uses linear relative motion between the

point cutting tool to machine a linear tool path. Its cut is an analogous to that of a

lathe, except that it is linear instead of helical. (Adding axes of motion can yie

paths, as also done in helical planning.) A shaper is analogous to a planner, but smaller, and with

the cutter riding a ram that moves above a stationary work piece, rather than the entire work

The ram is moved back and forth typically by a crank inside the

actuated shapers also exist.

MECHANICAL / IVSEM

e of machine tool that uses linear relative motion between the work piece

logous to that of a

motion can yield helical tool

ner, but smaller, and with

piece, rather than the entire work

ved back and forth typically by a crank inside the


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PLANER MACHINE

A planer is a type of metalworking machine tool that uses linear relative motion between

the work piece and a single-point cutting tool to machine a linear tool path. Its cut is analogous

to that of a lathe, except that it is linear instead of helical. (Adding axes of motion can yield

helical tool paths; see "Helical planing"below.) A planer is analogous to a shaper, but larger, and

with the entire work piece moving on a table beneath the cutter, instead of the cutter riding a ram

that moves above a stationary work piece. The table is moved back and forth on the bed beneath

the cutting head either by mechanical means, such as a rack and pinion drive or a lead screw, or

by a hydraulic cylinder.

DRILLING MACHINE

A drill or drill motor is a tool fitted with a cutting tool attachment or driving tool

attachment, usually a drill bit or driver bit, used for drilling holes in various materials or

fastening various materials together with the use of fasteners. The attachment is gripped by a

chuck at one end of the drill and rotated while pressed against the target material. The tip, and


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sometimes edges, of the cutting tool does the work of cutting into the target material. This may

be slicing off thin shavings (twist drills or auger bits), grinding off small particles (oil drilling),

crushing and removing pieces of the work piece (SDS masonry drill), countersinking, counter

boring, or other operations. Drills are commonly used in woodworking, metalworking,

construction and do-it your self projects. Specially designed drills are also used in medicine,

space missions and other applications.

BORING MACHINE

In machining, boring is the process of enlarging a hole that has already been drilled (or

cast), by means of a single-point cutting tool (or of a boring head containing several such tools),

for example as in boring a cannon barrel. Boring is used to achieve greater accuracy of the

diameter of a hole, and can be used to cut a tapered hole. There are various types of boring. The

boring bar may be supported on both ends (which only works if the existing hole is a through

hole), or it may be supported at one end. Line boring (line boring, line-boring) implies the


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former. Back boring is the process of reaching through an existing hole and then boring on the

"back" side of the work piece (relative to the machine headstock).

MILLING MACHINE


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A milling machine (also see synonyms below) is a machine tool used to machine solid

materials. Milling machines are often classed in two basic forms, horizontal and vertical, which

refers to the orientation of the main spindle. Both types range in size from small, bench-mounted

devices to room-sized machines. Unlike a drill press, this holds the work piece stationary as the

drill moves axially to penetrate the material, milling machines also move the work piece radially

against the rotating milling cutter, which cuts on its sides as well as its tip. Work piece and cutter

movement are precisely controlled to less than 0.001 in (0.025 mm), usually by means of

precision ground slides and lead screws or analogous technology. Milling machines may be

manually operated, mechanically automated, or digitally automated via computer numerical

control (CNC).Milling machines can perform a vast number of operations, from simple (e.g., slot

and keyway cutting, planning, drilling) to complex (e.g., contouring, die sinking). Cutting fluid is

often pumped to the cutting site to cool and lubricate the cut and to wash away the resulting

swarf.

GRINDING MACHINE

A grinding machine, often shortened to grinder, is a machine tool used for grinding,

which is a type of machining using an abrasive wheel as the cutting tool. Each grain of abrasive


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on the wheel's surface cuts a small chip from the work piece via shear deformation. The grinding

machine consists of a power driven grinding wheel spinning at the required speed (which is

determined by the wheel’s diameter and manufacturer’s rating, usually by a formula) and a bed

with a fixture to guide and hold the work piece. The grinding head can be controlled to travel

across a fixed work piece or the work piece can be moved whilst the grind head stays in a fixed

position. Very fine control of the grinding head or tables position is possible using a Vernier

calibrated hand wheel, or using the features of numerical controls.

machine tools laboratory (14ame15)

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