SSN EPL Mechanical - Manual

SSN College of Engineering Rajiv Gandhi Salai, SSN Nagar

Kalavakkam – 603 110

Certificate

Date:

Certified Bonafide Record of work done by …………………………………………….

Register number …….………………. of I Semester ………………………………

…………………………. Branch during Aug – Dec, 2011.

HOD Faculty

Submitted for the university practical examination held on …………………….

Internal Examiner External Examiner

Ex. No. Date Title of the Experiment Page

No. Marks Faculty

Signature CARPENTRY 1

1 TEE or Middle Lap Joint 13

2 Cross Lap Joint 15

3 Dovetail joint 17

4 Mortise and Tenon Joint 19

WELDING 21

1 Double VEE Butt Joint 30

2 Tee Joint 32

3 Lap Joint 34

MACHINING 36

1 Turing, Facing and Chamfering 51

2 Step Turning 53

3 Taper Turning 55

4 Hole Drilling 57

PLUMBING 59

1 Basic pipe connection 69

2 Mixed pipe connection 71

3 Connection of G.I pipes 73

SHEET METAL WORK 75

1 Making of Rectangular Tray 81

CONTENTS

CARPENTRY

1

SAFETY PRECAUTIONS FOR CARPENTRY WORK

1. Always keep sufficient distance between the working table and yourself while

planning.

2. Boards and other wooden pieces carrying nails should never be allowed to remain

on the floor.

3. Chisels and other pointed tools having sharp edges pointing towards the edge of

the table should not be kept on the table.

4. Test the sharpness of the cutting edge on wood or paper not by your hand.

5. Tools, which are not being used, should always be kept at their respective places.

6. Care should be taken when you are using your thumb as a guide in cross cutting

and ripping.

7. Examine wood for knots and other defects before placing it in the planer.

8. Do not plane against the grain of the wood.

9. Keep the screwdrivers properly pointed to prevent injury to hands.

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Ex. No. : 1

Date : Name of the Job: TEE or Middle Lap Joint

Aim: To make a T-joint of the required dimension from the given wooden piece.

Material required:

1. 310 x 45 x 45 mm wooden block

Tools required:

1. Metal jackplane 2. Mallet 3. Scriber 4. Marking gauge

5. Try square 6. Ripsaw 7. Firmer chisel 8. C- Clamp

9. Steel rule 10. Carpentry vice.

Sequence of Operations:

1. Checking the dimensions 2. Planning 3. Right angle checking

4. Marking 5. Sawing or Cutting 6. Chiseling

7. Finishing

Procedure:

1. The given job is checked to ensure its correct size.

2. The job is firmly clamped in the carpentry vice and any two adjacent surfaces are

planed by Jackplane to get right angle.

3. Using try square, the right angle of the work piece is checked.

4. All the four sides of the wooden pieces are planed to get the smoother and finished

surface.

5. The job is cut into two halves using Ripsaw then proper marking is done for T- joint

on the two pieces using steel rule and marking gauge.

6. Using tenon saw and firmer chisel the unwanted portions are removed as per the

drawing from the two pieces.

7. Now the two pieces are assembled to check proper fitting.

8. The finished job is again checked for its accurate shape and size using try square and

steel rule.

Result:

Thus, the desired T-joint is made.

Signature of Staff Signature of Instructor

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TEE or MIDDLE LAP – JOINT

All dimensions are in mm

Cutting & Chiseling

Finishing

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Ex. No. : 2

Date : Name of the Job: Cross Lap Joint

Aim: To make a cross lap joint of the required dimension from the given wooden piece.

Material required:


Tools required:







7. Finishing

Procedure:






surface.

5. The job is cut into two halves using Ripsaw then proper marking is done for the cross

lap joint on the two pieces using steel rule and marking gauge.





steel rule.

Result:

Thus, the desired cross lap joint is made.


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CROSS LAP – JOINT


Cutting & Chiseling

Finishing

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Ex. No. : 3

Date : Name of the Job: Dovetail Joint

Aim: To make a dovetail joint of the required dimension from the given wooden piece.

Material required:


Tools required:







7. Finishing

Procedure:






surface.

5. The job is cut into two halves using Ripsaw then proper marking is done for dovetail

joint on the two pieces using steel rule and marking gauge.





steel rule.

Result:

Thus, the desired dovetail joint is made.


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DOVETAIL – JOINT

`


Cutting & Chiseling

Finishing

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Ex. No. : 4

Date : Name of the Job: Mortise & Tenon Joint

Aim: To make a mortise and tenon joint of the given dimensions.

Material required:


Tools required:







7. Finishing

Procedure:






surface.

5. The job is cut into two halves using Ripsaw then proper marking is done for mortise

and tenon joint as per the drawing on the two pieces using steel rule and marking

gauge.





steel rule.

Result:

Thus, the desired mortise and tenon joint is made.


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MORTISE & TENON – JOINT


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WELDING

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GENERAL SAFETY PRECAUTIONS FOR WELDING

To prevent injury to personnel, extreme caution should be exercised when using any types of

welding equipment. Injury can result from fire, explosions, electric shock, or harmful agents.

Both the general and specific safety precautions listed below must be strictly observed by

workers who weld or cut metals.

1. Check the ground connection and insulation of all the wires.

2. The arc produced should be observed only through the shielding glass.

3. Always wear the safety hand gloves, apron and leather shoes.

4. Use proper current capacity cables.

5. Remove all flammable material, such as cotton, oil, gasoline, etc., from the vicinity of

welding.

6. Be sure that hot sparks or hot metal will not fall on the operator or on any welding

equipment components.

7. Switch off the welding machine when leaving from the work.

8. Do not leave hot rejected electrode stubs, steel scrap, or tools on the floor or around

the welding equipment. Accidents and/or fires may occur.

9. Remove the slag by chipping hammer only.

10. To relive strain or irritation on the eyes, eye drops may be applied.

11. Keep a suitable fire extinguisher nearby at all times. Ensure the fire extinguisher is in

operable condition.

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Ex. No. : 1

Date : Name of the Job: Double VEE Butt Joint

Aim: To make a double V-butt joint using arc welding on the given work pieces.

Material required:

1. Mild Steel (M.S) plate of size 100 x 50 x 06 mm – 02 Nos.

Tools required:

1. Power supply (AC/DC) 2. Welding torch 3. Electrodes 4. Tongs

5. Chipping hammer 6. Wire brush 7. Gloves 8. Apron

9. Shield 10. Goggles 11. Earth clamp


1. Edge preparation (Filing to remove rust, scale, etc.) 2. Tacking

3. Welding 4. Cooling 5. Chipping 6. Cleaning

Procedure:

1. First of all, the workpieces must be thoroughly cleaned to remove any rust, scale and

other foreign materials by filing.

2. Then the given workpieces are placed in such a way that it forms a V and an inverted

V shape when the plates butt each other (as shown in Fig.).

3. Appropriate power supply should be given to the electrodes and the workpiece.

4. Now, the welding current output may be adjusted as necessary.

5. When the current is passed, arc is produces between the electrode and the workpieces.

6. Set the workpieces in correct position and maintain the appropriate gap of 1-2 mm

and start tack welding at both the ends of the workpieces.

7. The welding is carried out throughout the length.

8. Now, the partially welded plates are inverted and the welding is carried out again

throughout the length.

9. As soon as the welding process is finished, the current supply is switched off.

10. Leave the workpiece untouched in air for at least 10 minutes for cooling.

11. Slags are removed by chipping process with the help of chipping hammer.

12. Finally using wire brush, welded portions are cleaned.

Result:

Thus, the desired Double V-butt joint is obtained using arc welding.


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Double Vee Butt Joint


Welding symbol

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Ex. No. : 2

Date : Name of the Job: TEE Joint

Aim: To make a TEE joint using arc welding on the given work pieces.

Material required:


Tools required:







Procedure:



2. Then the given workpieces are placed in such a way that it forms a T-shape (The

workpieces are standing at right angles to each other as shown in Fig.) with the help

of flat tongs and try square.





and start tack welding at both the ends of the workpieces.

7. The welding is carried out throughout the length on both the sides at the bottom of the

vertically standing plate.





Result:

Thus, the desired TEE joint is obtained using arc welding.


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Tee Joint


Welding symbol

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Ex. No. : 3

Date : Name of the Job: LAP Joint

Aim: To make a lap joint using arc welding on the given work pieces.

Material required:


Tools required:







Procedure:



2. Then the given workpieces are placed in such a way that the two workpieces are

overlapped one over the other as shown in Fig.





and start tack welding at both the ends of the workpieces as shown in Fig..

7. The welding is carried out throughout the length.

8. Now, the partially welded plates are inverted and the welding is carried out again

throughout the length.





Result:

Thus, the desired lap joint is obtained using arc welding.


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Lap Joint


Welding symbol

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MACHINING

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SAFETY PRECAUTIONS FOR CENTRE LATHE

All lathe operators must be constantly aware of the safety hazards that are associated with

using the lathe and must know all safety precautions to avoid accidents and injuries.

Carelessness and ignorance are two great menaces to personal safety. Other hazards can

be mechanically related to working with the lathe, such as proper machine maintenance

and setup. Some important safety precautions to follow when using lathes are:

� Correct dress is important, remove rings and watches, and roll sleeves above

elbows.

� Always stop the lathe before making adjustments.

� Do not changes spindle speeds until the lathe comes to a complete stop.

� Handle sharp cutters, centers, and drills with care.

� Remove chuck keys and wrenches before operating

� Always wear protective eye protection.

� Handle heavy chucks with care and protect the lathe ways with a block of wood

when installing a chuck.

� Know where the emergency stop is before operating the lathe.

� Use pliers or a brush to remove chips and sward, never your hands.

� Never lean on the lathe.

� Never lay tools directly on the lathe ways. If a separate table is not available, use

a wide board with a cleat on each side to lay on the ways.

� Keep tools overhang as short as possible.

� Never attempt to measure work while it is turning.

� Never file lathe work unless the file has a handle.

� File left-handed if possible.

� Protect the lathe ways when grinding or filing.

� Use two hands when sanding the work piece. Do not wrap sand paper or emery

cloth around the work piece.

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CENTRE LATHE

Introduction:

Lathe is a machine tool which is used to perform several operations on the work piece. Lathe is useful in making several parts which is further assembled to make new machine. I-fence lathe is known as “mother of machines”.

Turning

Turning is the machining operation that produces cylindrical parts. In its bathe form, it can be defined as the machining of an external surface:

1. with the work piece rotating. 2. with a single-point cutting tool, 3. And Taper turning is practically the same, except that the cutter path is at an angle to the work axis. Similarly, in contour turning, the distance of the cutter from the work axis is varied to produce the desired shape.

Even though a single-point tool is specified, this does no exclude multiple-tool setups, which are often employed in turning. In such setups, each tool operates independently 4 a single-point cutter.

BASIC WORKING PRINCIPLE OF LATHE

In lathe, the work piece is held in the chuck, a work holding device. The cutting tool is mounted in the tool post. The chuck is rotated by means of power. When the chuck rotates, the work piece also rotates. The tool is moved against the rotating work piece by giving small amount of depth of cut. The material is removed in the form of chips. Continuous feed and appropriate depth of cut is given until the required dimensions of the work piece are obtained.

TYPES OF LATHE MACHINES

There are different types of lathe machines. They are

1. Centre lathe

2. Tool room lathe

3. Bench lathe

4. Capstan lathe

5. Turret lathe

6. Automatic lathe

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DESCRIPTION OF A LATHE

Lathe is a machine which is made up of several parts. They are

1. Bed

It is the base of the machine. On its left side, the head stock is mounted. A movable casting called tail stock is mounted on the right side. The legs of the bed have holes to bolt down and grout the lathe.

It consists of a spindle, gears and speed change levers. It is used to transmit the motion to the job. There are two types of headstock. 1. Belt driven headstock 2. Geared headstock

Tailstock

The tailstock is fixed to the right end of the bed. This supports work when turning between centers. It is also used for supporting and feeding drills, reamers etc. The main body is cast-iron. The barrel of the tailstock has a mores taper hole to accommodate centres, taper sleeves and taper shank drills. In its normal position, the tailstock centre is in line with that of the head stock. An adjustment is provided for setting the tall stock centre to one side for taper turning.

The tailstock can be clamped at various positions along the bed to accommodate work pieces of various lengths.

The Carriage (or) Saddle

The carriage forms the base of the unit which supports the cutting tool. Carriage can be traversed (slide along) along the whole length of the bed by hand control or by power feed.

Apron is attached to the front part of the carriage. Apron contains the mechanisms for moving the saddle and cross slide. The combined carriage and apron is called the saddle.

Cross slide

The cross slide is the part fixed to the top of the carriage. Cross slide is provided for cross traversing. Cross slide moves at right angles to the bed. It is normally used for feeding and facing.

The compound slide

The compound slide is secured to the cross slide and has two main functions.

1. To provide location and support for the tool post.

2. To enable the tool to be placed at an angle to the axis of the spindle.

The compound slide (top slide) is mounted on the cross-slide. The slide is capable of being rotated on a swivel base. The swivel base is marked with a protractor scale. This enables the path of the tool to be inclined to the axis of the lathe. This is simple way of turning tapers and chamfers with a wide range of included angles.

The lead screw

The lead screw is the top shaft lengthwise at the front of the lathe bed. It ha square thread. When screw cutting, the leads crew is used for causing automatic lengthwise traveled the tool. It gets its drive from the screw-cut gearbox attached to the headstock.

The feed shaft is the bottom shaft running length wise at the front of the lathe bed. When the shaft is rotating and when the automatic tray lever is engaged; the whole carriage slides travels automatically along the bed.

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WORK HOLDING DEVICES

Lathe Centres

They are used to support work. It has two categories of centres. Live centre is one which is fitted in the headstock spindle. Dead centre is one which is fitted in the tail stock.

Chuck

It is a device used to hold a job. It is easily fitted on the thread cut on the end of headstock spindle.

Various types of chuck are

(a) Two jaw chuck (b) Three jaw chuck

(c) Four jaw chuck (d) Collet chuck (e) Magnetic chuck

Lathe carriers or bogs

It is used for transferring the motion from the rotating driving plate to the work held between the centres.

Catch plate

It is a plain disc of steel or cast iron. It is screwed to the nose of the headstock spindle.

It is used to drive the work piece through a carrier or dog when it is held between the centres.

Face plate

It is a circular plate\and it is screwed to lathe spindle. It is used for mounting the type of jobs which cannot be held by chucks. There are number of holes and slots on the face of the face plate.

Steady Rest

It supports long work piece when machined between the centres or by a chuck.

It is used for cylindrically long jobs. Two types of steady rest are

a. Fixed steady rest

b. Traveling steady rest

Mandrel

It is used for holding hollow jobs. It is a hardened piece of round bar for holding bored or reamed jobs. It has drill holes at both the ends. Work piece is mounted over the mandrel and the mandrel is rotated between centres.

Follower rest

It is made of cast iron and is used for supporting long slender work pieces, against the cutting tool forces. It can be clamped to the carriage of the lathe, to make it travel along with the cutting tool. It has two adjustable jaws to support the work piece the two supporting jaws of the rest, resist the cutting forces. To reduce the damage to the finished surface of the job, the jaws are normally made of brass.

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MARKING AND MEASURING TOOLS

The following table illustrates various marking and measuring tools and their characteristics and uses.

1. Steel Rule

It is made of tempered steel about 3/64 inch thick, 3/4 inch wide and 6 inch long with several styles of graduation. It is used to take linear measurements up to accuracy of 0.5mm.

2. Vernier Caliper

Graduations are made on both sides of the bar. It is a tool for checking inside and outside measurements. It is also used as depth gauge.

3. Vernier Height Gauge

It consists of an upright steel bar fixed to a steel base. On the bar, there is a movable jaw with vernier scale. The screw is used to adjust the vernier scale to a required position. It is used to scribe lines on a work piece to known heights.

4. Scriber

A scriber is a sharp pointed steel tool. It is made of carbon tool steel. It is used to scribe or mark lines on metal work pieces.

5. Try square

It is a small, light square that has a hardened steel blade without graduations. It has two parts namely blade, beam. Try square is used to check the flatness and square ness of the work piece.

6. Dot Punch

It is made of Steel. The angle of the conical point is usually 60°.

It is used to make dots along marked lines and to provide small centre mark for divider point etc.,

7. Surface Plate

It is made of grey cast iron and of solid design (or) with ribs. It is used for testing the flatness of work and also used for carrying the work piece while marking.

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CUTTING TOOLS USED

For making a finished job on lathe machine, various types of cutting tools are used. One of them is single point cutting tool which is used to perform several operations on the work piece. Various types of cutting tools are

Facing tool: It is used for facing the longitudinal ends of the job. Its shape is like a knife,

Rough turning tool: It is used to remove excess material from the work piece in quick time. It can be used to give large depth of cut and works at coarse feed.

Radius tool: Jobs which need round cutting are done with this tool. Their types are

1. Concave radius tool 2. Convex radius tool

FINISHING TOOL

It is used for getting smooth finish on the work piece. Its point is a little more round.

Drill tool: It is used for making holes of various diameters on the job. Drill bit of various sizes of diameter are available.

Boring tool: It is used for enlarging the drilled hole.

Knurling tool: Drawing slanting or square projecting lines on the surface of a job is known as knurling. It is used for making better grip on the surface of a job.

Parting tool: It is used to cut the job into two parts. It is also used for grooving.

Form turning tool: It is used for jobs which require both convex and concave turning.

Thread cutting tool: It is used for making internal or external threads on the work piece.The tool nose are designed with a definite profile for taking threads.

CUTTING TOOLS ANGLES

Top Rake Angle (Back rack angle)

If the slope is given to the face or surface of the tool and if this slope is along the tool’s length then it is called top rake angle. It is usually 15° to 20°.

Side Rake Angle

If the slope is given to the face or top of the tool along the tool’s width then it is called side rake angle. It lies between 6° and 15°.

Clearance Angle (Relief angle)

Types: (i) Side clearance angle and (ii) End clearance angle. They are provided to keep the surface of the tool clear of the work piece.

TOOL MATERIALS

The single point\lathe cutting tools are made of high speed steel (H.S.S.).The main alloying elements in 18-4-1 HSS tools are 18 percent tungsten, 4 percent chromium and 1 percent vanadium. 5 to 10 percent cobalt is also added to improve the heat resisting properties of the tool. General purpose hand cutting tools are usually made from carbon steel or tool steel. Carbide tipped tools fixed in tool holders, are mostly used in production shops

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LATHE OPERATIONS

Facing: It is done for getting fine finish (good surface finish) on the face of the job. Facing tool is set at an angle to the work piece. The tool is fed from the centre of work piece towards the outer surface against the rotating work piece. Depth of cut is low for the facing operation. For getting fine finish, power feed can be used.

Plain Turning: It is done for reducing the diameter of the work piece. A cutting tool with 70° setting angle is used for roughing operation. More feed is given for rough turning while less feed is given for finishing. Work piece is held in chuck and tool is set to the centre height of the work piece.

Taper turning: Taper turning is different from the turning operation. Taper is defined as the uniform change in the diameter of a work piece measured along its length.

Taper = D-d / 2l, θ = tan-1 (D-d) / 2l

D is large diameter, d is small diameter and L is length of taper

Taper turning can be done by the following methods

Where, 1. Compound rest method 2.Tailstock se over method.3. Using form tool

4. Taper attachment method.

Step turning: It is similar to the process of turning but in this case different diameters in step of various sizes are taken on the work piece. In initial stage, roughing tool is used while a knife tool is used for the finishing cut.

Boring: It is a process of enlarging a drilled hole. A special type of boring tool is used for this purpose.

Tapping: It is a process of making internal threads in small jobs. Tap is held in a tail stock and the job is held in a chuck. Feed is given by rotating tail stock hand wheel.

Grooving and Parting off: It is done at the end of the threaded portion. It is fed crosswise against the rotating work piece. Parting off is done by parting tool.

Thread cutting: It is a process of making threads on the work piece. Thread cutting tool is used for this operation. Power feed is given to the carriage through lead screw and for one rotation of the job; it covers the distance equal to the pitch. Depth of cut is small for thread cutting.

Knurling: It is a process of making serrations on the work piece. Knurling tools of different shape and size are used to make grip on the work piece. It has two hardened steel rollers. The tool is held in the tool post and pressed against the rotating work piece. Work piece is rotated at lower speed and small amount of feed is given.

Drilling: It is a process of making a hole on the work piece. Job is held in a chuck while the drill is held in the tailstock sleeve. Feed is given by rotating the hard wheel in the tailstock which pushes the tailstock sleeve.

Chamfering: It is a beveling or turning a slope at the end of work piece. It is done for jobs after knurling, rough turning, thread cutting to remove the burrs. It is normally performed on bolts, nuts.

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THE BENCH (SENSITIVE) DRILLING MACHINE

1. The simplest type of drilling machine is the bench drilling machine.

2. It is capable of accepting drills up to 12.5 mm diameter.

3. These machines have the chuck mounted directly on to the spindle nose taper. Variations in spindle speed are achieved by altering the belt position on the stepped pulleys.

Drilling: Drilling is the process of machining a round hole in a work piece. Drilling is making a cylindrical hole to a given size in a workspace. Drilling is possible by removing chips of material with a double-edged cutting tool.

Twist Drill: A twist drill is machine-rotated tool with cutting edges. The cutting edges produce circular holes in metal, plastics and wood etc.The twist drill is made of high speed steel (HSS) and heat-treated. The twist drill has two spiral grooves. A twist drill has double cutting edges. Twist drill is a spiral, fluted cylinder with cutting lips on one end, The Cutting force is provided by rotating the dill against a stationary work piece. Chips cut at the bottom of the hole a carried away by the flutes as the drill is fed into the work piece to progressively increase the hole depth. The flutes e serves as a passage for cutting fluids.

Shank: Shank is the part that fits into the drilling machine is called the shank. There are

1. straight-shank and 2. taper shank twist drills. This taper on shank is called morse taper.

Heel: Heel is the tail end of the helix.

Land: Land is the narrow part of the body. Land bears on the sides of the hole to give guidance.

Lip: Lip is the cutting edge. The two lip lengths must be equal if over size hole are to be avoided. Lead is the same as the pitch of a screw thread. Chisel edge is the cutting edge. The chisel edge angle should be about 130°.

Drill Point: i) The actual cutting of a hole takes place at the drill point and not at the edges.

ii) The drill point geometrics (or) shapes differ according to the demands of the drilling operations and the kind of material being drilled.

Point angle is disposed exact equally either side of the drift axis. Point angle is normally 118°. Designers arrange the shape of the flute so that when the point angle 118°, the lip or cutting edge is a straight line.

Clearance angle: For general purposes the clearance angle, measured at the periphery of the drill, should be from 10° to 12°.

Drill materials: Drills are made of high speed steel. Some drills are tipped with titanium nitride coatings (or) carbide tips improve drilling capabilities. The coatings help to increase the life of drills. A number of different types of drills are employed in industrial production. The section of a specific drill type is dependent on

i) The material being drilled

ii) Diameter

iii) Shape and depth of hole

iv) Whether the hole is originated or enlarged

v) The type of machinery being used.

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Ex. No. : 1

Date : Name of the Job: Facing, Turning and Chamfering

Aim: To obtain the required shape and size out of the given workpiece by different lathe

operations.

Material required:

1. Cylindrical work piece of diameter 25 mm and length 105 mm mild steel rod.

Tools required:

1. Centre lathe

2. Cutting Tool

3. Steel rule

4. Vernier Caliper

5. Vernier Height gauge

6. Surface plate

7. Angle plate


1. Checking the workpiece

2. Work piece setting

3. Tool setting

4. Facing

5. Turning

6. Chamfering

7. Finishing

Procedure:

1. The given work piece is checked for its dimensions.

2. The work piece is held in the three-jaw chuck and with the help of chuck key tightens

the work piece firmly. Ensure the job is fully centered.

3. The single point cutting tool is held in the tool post and tightens the nuts using

spanner.

4. Facing is done with cutting tool moving from the center of work piece towards

outside. It is done until the required length of the job is obtained. i.e. movement of the

cutting tool is perpendicular to lathe axis

5. Turning is done to reduce the diameter of the job. Sufficient depth of cut is given and

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it is done until the required diameter of the job is obtained. i.e. movement of the

cutting tool is parallel to lathe axis.

6. Chamfering is done on the edges to avoid sharp edges. For that the tool is held 45 to

the lathe axis and fed against the rotating work piece.

7. Finally, the dimensions of the work piece are again checked.

Result:

Thus the required size and shape of the given work piece is obtained and checked for

its dimensions.


Facing, Turning, and Chamfering


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Ex. No. : 2

Date : Name of the Job: Facing, Step Turning and Chamfering


operations.

Material required:


Tools required:

1. Centre lathe

2. Cutting Tool

3. Steel rule

4. Vernier Caliper


6. Surface plate

7. Angle plate




3. Tool setting

4. Facing

5. Turning

6. Chamfering

7. Finishing

Procedure:





spanner.


outside. It is done until the required length of the job is obtained. i.e. movement of the

cutting tool is perpendicular to lathe axis


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it is done until the required diameter of the job (different diameter in different length

segments) is obtained. i.e. movement of the cutting tool is parallel to lathe axis.




Result:


its dimensions.


Facing, Step Turning and Chamfering


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Ex. No. : 3

Date : Name of the Job: Facing, Taper Turning and Chamfering


operations.

Material required:


Tools required:

1. Centre lathe

2. Cutting Tool

3. Steel rule

4. Vernier Caliper


6. Surface plate

7. Angle plate




3. Tool setting

4. Facing

5. Turning

6. Chamfering

7. Finishing

Procedure:





spanner.


outside. It is done until the required length of the job is obtained.


it is done until the required diameter of the job is obtained.

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6. Taper Turning (changing diameter along the length) is done on the work piece, as per

the Taper angle already calculated. Then the compound rest base is swiveled and set

at half taper angle. Cutting tool is moved at an angle to the lathe axis. Tool is moved

by compound rest hand wheel. The taper angle = L

dD

2tan 1 . Here D – Major

diameter, d – Minor diameter and ‘L’ is length of taper turning.




Result:


its dimensions.


Taper angle = 402

1824tan 1

x = 0.075 rad or 4.3

Facing, Taper Turning and Chamfering


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Ex. No. : 4

Date : Name of the Job: Drilling of Holes

Aim: To drill the holes of required diameter in the given mild steel plate using a drilling

machine.

Material required:

1. Mild steel flat plate of dimension 51 mm x 51 mm x 6 mm

Tools required:

1. Steel rule

2. Vernier caliper

3. Surface plate

4. Flat file

5. Scriber

6. Centre

7. Punch

8. Hammer

9. Try square

10. 8 mm and 12 mm drill bits.



2. Filing


4. Tool setting

5. Drilling

Procedure:


2. The work piece is fixed in a bench vice and the four sides are filed in order to bring

down to the required size and square shape.

3. The work piece is held on the surface plate and using scriber the lines are marked on

the plate.

4. At the required positions, the drilling centers are marked using a centre punch and

hammer.

5. The plate is then fixed on a drill vice firmly.

57

6. The 8 mm drill bit is fixed in the drill chuck and four holes at the marked places

are drilled by manual feed.

7. The edges of the drilled holes are countersunked by using a 12 mm drill bit in the

same drilling machine.

Result:

Thus, the desired holes are drilled in the given mild steel plate.


DRILLING HOLES


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PLUMBING

59

SAFETY PRECAUTINS IN PLUMBING

1. Switch off the motor while doing plumbing work.

2. Make sure that there is no leakage after connecting the pipes and other pipe

layout.

3. Close the gate valve to prevent the water supply from the main tank and carry out

plumbing work.

4. Use proper tool for the job. Never use spanner in place of hammer.

5. Always use proper spanner for proper nut or bolt.

6. File should be used with proper handle.

7. Never use chisels having mushroom heads.

8. Never hold the work in your hand while using a screwdriver.

9. Never strike with hammer on the handle of screwdriver.

10. Handle the plumbing tools with care since they are hard tools.

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1 Introduction

Plumbing is the art of design, installation and maintenance of pipe, pipe fittings and

other accessories in a building. It plays a major role in the construction of every

building. Plumbing includes the pipes, fixtures and accessories which carry water

from the main source of supply to the building. It also conveys the used fluids from a

building to other place of local disposal. Water distribution system consists of a

supply pipe leading to a fixture and a drain pipe taking the used water away.

2 Purpose of Plumbing

Plumbing is installed in a building for the comfort and convenience of the inhabitants

as well as sanitation and health. Water is brought by supply pipes and used water is

carried away by the drainage pipes. Good plumbing is necessary in houses,

apartments, commercial and other public buildings.

3 Tools used by Plumber

3.1 Pipe Vice

It is used to hold the pipe during cutting, marking, threading, etc.

It consists of a fixed jaw, a movable jaw and a screw handle for adjustment of

moving jaw.

3.2 Pipe Wrench

It has a fixed bottom jaw (called Heel jaw) attached to a lever handle.

The top jaw (called Hook jaw) is a movable by means of an adjustable nut.

It is available in different sizes.

Screw handle

Fixed Jaw

Movable jaw Base

Body

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3.3 Open End Spanner

Plain open end spanners are of solid non-adjustable type with openings at each

end.

These are made in a set.

3.4 Hacksaw Frame with Blade

It is bow shaped adjustable or rigid frame with a cutting blade.

The blade is made of carbon steel properly tempered and has teeth on one or

both the edges.

3.5 Pipe Threading Dies

It is also called as stocks and dies

Two types of dies are available, namely solid and adjustable.

They are fitted into the centre of the frame. Dies are held in position by a

block which is adjustable by means of a tommy bar.

This stock cuts parallel threads.

Separate set of dies are required for each size.

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4 Pipe Fittings

A lot of pipe fittings are used for joining pipes of larger size with flanges, while

smaller size pipes are joined by coupling some.

4.1 Coupling

It’s a short cylindrical sleeve with internal threads throughout its length.

It is used for joining two pipes in a straight line and where at least one pipe

can be turned.

It is available in different materials and different sizes.

4.2 Elbow

It is similar to the Coupling. It is used for fitting two pipes at right angles.

Internal threads are cut in the elbow.

It is also available in different material and different sizes.

4.3 TEE

It is used for giving connection from the main pipe line to a branch line.

By using it, two more lines can be made from the same supply line.


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4.4 Four-way Cross

It has a shape of + sign.

It is used for fitting a pipe in all four directions.

Threads are cut in all its four ends.


4.5 Pipe Union

It connects two pipes

Water meter is fitted with union so that they can be removed easily.

It provides facility to disconnect pipes.

It is available in different material and different sizes.

4.6 Reducer

It is used to connect a big pipe to a small pipe or vice versa face to face

It is available in different sizes and different materials.

4.7 Plug or Dummy

It is a short piece with external threads at one end and square end on another

end.

Square end enables the use of spanner to fasten it. 64

Used to screw onto a threaded opening for temporary closing.

A cap may be used for closing external threaded openings temporarily


4.8 Valves

Pipes can be joined with valves and according to our needs, we can stop or

open the flow of water through the pipes.

It is available in different materials and sizes.

4.9 Cock

It is also called as tap.

It serves the purpose of putting off or on the flowing water through pipes.

It is made up of copper, plastic, gun metal, etc.

At its top, there is a provision for starting the flow of water and insider there is

a cock.

It is available in different sizes.

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5 Types of pipes used in plumbing

66

Study of pipe connections on the suction pipe layouts

1. Laying pipe connection to the suction side of a pump – Inlet

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2. Laying pipe connection to the delivery side of a pump – Outlet

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Ex. No. : 1

Date : Name of the Job: Basic Pipe Connection

Aim: To make a Basic pipe connection using the given fittings as per the layout

Material required:

1. ½” Gate Valve (Brass)

2. ½” G.I Elbow

3. ½” G.I Tee

4. ½” G.I Dummy

5. ½” G.I Coupling

6. ½” M.S. Tap

7. ½” PVC pipe 1 feet – 3 Nos.

Tools required:

1. Pipe Vice

2. Pipe Wrench

3. Die Set ½”

4. Spanner 10-11

5. Hacksaw frame with Blade

Procedure:

1. Assemble the die set with ½” die and diestock correctly.

2. Hold the ½” PVC pipe with use of pipe vice

3. Make the threading operation on both sides

4. Repeat the threading operation in the remaining two pipes

5. Take one ½” PVC pipe and connect the ½” Gate valve (brass) on one side and

connect the G.I elbow another side.

6. Take another ½” PVC pipe and connect it to ½” G.I elbow and ½” G.I Tee

7. Take another ½” PVC pipe connect it to ½” G.I Tee and ½” G.I coupling.

8. Plug the ½” G.I Dummy in ½” G.I tee and connect the ½” M.S. Tap with ½” G.I

coupling.

9. Tight the all fittings with the use of pipe wrench.

Result:

The basic pipe connection is done using the given pipes and fittings as per the layout.


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Basic Pipe Connection

70

Ex. No. : 2

Date : Name of the Job: Mixed Pipe Connection

Aim: To make a Mixed pipe connection using the given fittings as per the layout

Material required:

1. ¾” G.I Elbow and Union

2. ¾” G.I Cross

3. ¾” – ½” G.I Reducer

4. ½” G.I. Coupling

5. ½” M.S. Tap

6. ¾” PVC pipe 1 feet – 3 Nos.

7. ½” PVC pipe 1 feet – 1 No.

Tools required:

1. Pipe Vice

2. Pipe Wrench

3. Die Set ¾”, Die set ½”

4. Spanner 10-11


Procedure:

1. Assemble the die set with ¾” die and diestock correctly.

2. Hold the ¾” PVC pipe with the use of pipe vice


4. Repeat the threading operation in the remaining two pipes

5. Assemble the die set with ½” die and diestock correctly

6. Hold the ½” PVC pipe with the use of pipe vice


8. Take one ¾” PVC pipe and connect the ¾” G.I elbow one side and connect the ¾” G.I

Union another side.

9. Take another ¾” PVC pipe and connect it to ¾” G.I Union and ¾” G.I Cross

10. Take another ¾” PVC pipe connect it to ¾” G.I Cross and ¾”- ½” G.I Reducer.

11. Take another ½” PVC pipe and connect it to ¾” – ½” G.I Reducer and ½” G.I Coupling

12. Connect the ½” M.S. Tap with ½” G.I Coupling.

13. Tight the all fittings with the use of pipe wrench.

Result:

The Basic pipe connection is done using the given pipes and fittings as per the layout.


71

Mixed Pipe Connection

72

Ex. No. : 3

Date : Name of the Job: Connection of Two G.I. Pipes

Aim: To make a G.I pipe connection using the given fittings as per the layout

Material required:

1. ½” G.I Coupling

2. ½” G.I. pipe 1 feet – 2 Nos.

Tools required:

1. Pipe Vice

2. Pipe Wrench

3. Die Set ½”

4. Spanner 10-11


Procedure:

1. Assemble the die set with ½” die and diestock correctly.

2. Hold the ½” G.I. pipe with the use of pipe vice

3. Make the threading operation on one side of the pipe.

4. Repeat the threading operation in the remaining pipe.

5. Take one ½” G.I pipe and connect the ½” G.I coupling with it.

6. Take another G.I pipe and connect it to the coupling pipe assembly.

7. Tight all the fittings with the use of a pipe wrench.

Result:

The Basic pipe connection is done using the given pipes and fittings as per the layout.


73

Connection of Two G.I. Pipes

74

SHEET METAL WORK

75

(i)

76

77

78

79

80

Ex. No. : 1

Date : Name of the Job: Making of Rectangular Tray

Aim: To make a rectangular tray from given sheet metal as per the given dimensions.

Material required:

1. 165 mm x 115 mm of 30 gauge G.I (Galvanized Iron) sheet.

Tools required:

1. Steel rule 2. Trammel 3. Scriber 4. Snips

5. Punch 6. Shears 7. Vice 8. Anvil

9. Stakes 10. Mallet 11. Cross peen hammer


1. Checking 2. Leveling 3. Laying out

4. Marking 5. Cutting 6. Bending

7. Hemming 8. Riveting 9. Finishing

Procedure:

1. The size of the given sheet is checked for its dimensions using a steel rule.

2. Then the sheet is leveled on the leveling plate using a mallet.

3. Develop the sheet metal as per the dimension of the tray.

4. The dimensions are marked as shown in fig.

5. The sheet is cut as per the marked dimensions by straight snips.

6. Then a single hemming is made on the four sides of the tray as shown in figure.

7. These four sides of the tray are bent to 90 using stakes anvil.

8. Finally all the corners of the tray are joined by riveting.

Result:

Thus the required shape of tray is obtained from the given sheet metal.


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Making of Rectangular Tray

Marking


After Cutting Finishing

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Documents

SSN EPL Mechanical - Manual