GOVERNMENT OF KERALA

DEPARTMENT OF TECHNICAL EDUCATION

LEARNING RESOURCE FOR

X STANDARD

WELDING TRADE

STATE INSTITUTE OF TECHNICAL TEACHERS

TRAINING & RESEARCH
HMT Jn., KALAMASSERY - 683104

Phone & Fax: 0484 2542355

Email: jd_cdc@yahoo.com, sitttr@gmail.com
Website: www.sitttrkerala.ac.in
 PREFACE
Government of Kerala introduced Technical High School system in 1961
with the aim of inculcating technical learning at the High School level so as to
produce technically talented youth. This would help students establish a strong
foundation in engineering studies so that they could pursue higher studies in
Engineering. Products of THS system can obtain employment at Craftsman level
too. In the emerging global economy there are ample employment opportunities
for technically qualified persons.

The revised THS curriculum which has been introduced in 2013 provides
maximum scope for the students to develop themselves into globally competitive
citizens who are abreast with the new advancements in the field of Science and
Technology. The medium change from Malayalam to English is an added
advantage to realize this objective.

Today, Welding has gone through a complete evolution with machine

playing a major role in every part of life. As the science continues to advance,
there are many advances in this area. There is a speedy development in industry
and new methods are being added day by day. This learning resource is prepared
with an objective of giving an understanding of welding, types of welding, weld
qualities etc, to the THS students.

The material is prepared in a language and style easily digestible to the

students of Technical High Schools. Several staff members of Technical
Education Department have contributed to the preparation of this learning
resource. I take this opportunity to extend my sincere gratitude to all of them.

N. SANTHAKUMAR
JOINT DIRECTOR
SITTTR, KALAMASSERY
 INSTRUCTIONS TO TEACHERS

The learning resource for imparting practical training in State trades and
NSQF specializations have been specially structured as follows:

The resource material is presented in two blocks—Block 1 and Block 2.

The key part is the Block 2, which provides the list of exercises to be carried
out for the student to practically learn the topic and acquire the appropriate skill.
But this process would require understanding the basic concepts and general
ideas in the topic. This is what is presented systematically in Block 1. Thus
Block 1 constitutes the theoretical concepts required for the exercises in
Block 2. Ths methodology to be adopted by the teacher in handling the practical
courses is listed below:

(i) Provide a general introduction to the subject from the appropriate

beginning portions of Block 1.

(ii) Proceed to Block 2. For each exercise in Block 2, identify the

concepts required for clearly understanding the practical work, teach
those from Block 1 and complete the practical work as detailed in
Block 2.

(iii) In the above manner, both the Blocks have to be completely

covered concurrently thereby ensuring that the students gain
competence in both practical as well as theoretical aspects, in a
systematic manner.

Suggestions for improvement of the structure and presentation of the

learning resource may be communicated to the undersigned or to the
Curriculum Development Centre, Kalamassery.

Dr. S. Radhakrishnan,
Chairman,
Learning Resource Committee for THS.
 LEARNING RESOURCE PREPARATION COMMITTEE

Chairman

Dr. S. Radhakrishnan, Principal, Govt. Engineering College,

Sreekrishnapuram.

Co-ordinator

Shri V A Shamsudeen, Deputy Director, SITTTR, Kalamassery

Asst. Co-ordinators

 Shri T. V. Francis, Project Officer, SITTTR, Kalamassery

 Shri Biju Peter, Project Officer, SITTTR, Kalamassery

Technical Expert Committee

 Shri. V P Sunny,Engineering Instructor, THS Thirssur

 Shri. John Wills N, Workshop Instructor, THS, Palakkad

Scrutinised by

 Shri. T O Thomas, HOS, SRGPTC, Thriprayar

Cover Design & Layout: Babu K. R, SITTTR, Kalamassery

 CONTENTS

BLOCK - I

CHAPTER 1 - WELDING MACHINE SPECIFICATION, EDGE PREPARATION &

WELDING SYMBOLS

1.1 Objectives … 1
1.2 Pedagogy … 1
1.3 Introduction … 1
1.4 Welding machine specification … 1
1.5 merits of AC welding machine … 2
1.6 Demerits of AC welding machine … 2
1.7 merits of DC welding machine … 2
1.8 Demerits of DC welding machine … 2
1.9 Edge preparation … 3
1.10 Welding symbols … 4
1.11 Test questions … 6

CHAPTER 2 - ARC AND GAS CUTTING

2.1 Objectives … 7
2.2 Pedagogy … 7
2.3 Introduction … 7
2.4 Theory of gas cutting … 7
2.5 Mechanism of arc cutting … 8
2.6 Electrode for arc cutting … 8
2.7 Test questions … 9

CHAPTER 3 - WELDING OF VARIOUS METALS AND WELDING DEFECTS

3.1 Objectives … 10
3.2 Pedagogy … 10
3.3 Introduction … 10
3.4 Ferrous metals welding … 10
3.5 Non ferrous metals welding … 11
3.6 Welding of alloys … 12
3.7 Welding defects … 12
3.8 Test questions … 15
CHAPTER 4 - SPECIAL WELDING PROCESSES AND ITS APPLICATIONS

4.1 Objectives … 16
4.2 Pedagogy … 16
4.3 Introduction … 16
4.4 TIG Welding … 17
4.5 Thermite Welding … 17
4.6 Resistance welding … 18
4.6.2 Seam Welding … 19
4.6.3 CO2 Arc Welding … 19
4.7 Test questions … 20

BLOCK - II

1. Exercise no 1 straight line depositing – vertical … 23

2. Exercise no 2 square butt joint – vertical … 25

3. Exercise no 3 single ‘v’ butt joint – vertical … 27

4. Exercise no 4 ‘t’ joint – vertical … 29

5. Exercise no 5 straight line depositing - over head … 31

6. Exercise no 6 Square Butt Joint - Over Head … 33

7. Exercise no 7 Round Fillet Joint … 35

8. Exercise no 8 Shaft Butt Joint … 37

 Welding

CHAPTER 1

WELDING MACHINE SPECIFICATION, EDGE PREPARATION &

WELDING SYMBOLS

1.1 Objectives

 To understand the specification of welding machine.

 To understand the need of edge preparation.
 To understand different methods of edge preparation.
 To understand different welding symbols.

1.2 Pedagogy

o Demonstration
o Use of smart classroom
o Practical class

1.3 Introduction

A welding machine is a device that provides an electric current to perform welding

process. Polarity, voltage and current ratings for welding process depend on the type of
material and thickness of metal to be weld. If AC power supply is readily available AC
Transformer and DC rectifier set is used. If AC supply is not available DC generators
are used for welding purpose.

Edge preparation is required to get full penetration and sufficient strength in welded
joints. To achieve full welding penetration, you must cut the edges of the metal. The
weld replaces the removed material and makes a complete bridge between the joining
parts.

1.4 Welding machine specification

For selecting an arc welding machine the following factors is to be considered:

Input voltage and number of phases

Input frequency (Hz)
Input power (KVA)

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Output current range (A)

Rated output voltage (V)
Efficiency of welding machine
Suitable range of electrodes
Overall dimension of welding machine and weight

If DC generators are used for welding purpose, following maters are also to be
considered

Open circuit voltage (No load voltage of generator)

Current range
Type of prime mover used

1.5 Merits of AC welding machine

Low initial cost

Low operating cost
Low maintenance cost due to absence of rotating parts
Higher working efficiency
Noiseless operation

1.6 Demerits of AC welding machine

Not suitable for bare and light coated electrodes

Chance for electrical shock
Not suitable for cast iron and non ferrous metals

1.7 Merits of DC machines

Required heat distribution is possible between base metal and electrode

Suitable for ferrous and non ferrous metals
Bare and light coated electrodes can be used
Positional welding is easy due to polarity advantage
Easy to maintain stable arc

1.8 Demerits of DC machines

High initial cost

Higher operating and maintenance cost
Noisy operation

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A lower working efficiency

1.9 Edge preparation

Edge preparation may be done by according to the thickness of the plates used in
welding process. The sheets up to 3 mm thicknesses are welded by flanged the edges
before welding. 3mm to 8mm sheets are need not any edge preparation. 8mm to 15mm
plates are joined by single V butt joint. Single U butt joint or Double U Butt joints are
used for joining metal plates more than 20mm.

Edge preparation is essential to ensure absolute fusion right through the joint and
maximum penetration

The joining edges may be prepared for welding by one of the following methods
mentioned below.

Flame cutting
Mechanical cutting
Machine grinding or hand grinding
Filing
Chipping

1.9.1 Type of Edge preparation

Fig. 1.1 Types of Edge Preparations

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Fig. 1.1 Types of Edge Preparations (contn.)

1.10 Welding symbols

Fig. 1.2 Welding Symbols

When it is required to represent a welded joint on drawing weld can be simply drawn as
it appears. Symbols are attached to a line with an arrow to the place of joint.

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1.10.1 Example:

Fig 1.3 Welding symbols

1.10.2 Table 1- Elementary symbols

Sl
Designation Illustration Symbol
No.
Butt weld between plates with raised edges (the
1 raised edges being melted down completely)

2 Square butt weld

3 Single V butt weld

4 Single bevel butt weld

5 Single V butt weld with broad root face

6 Single bevel butt weld with broad root face

7 Single U butt weld (parallel or sloping sides)

8 Single J butt weld

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9 Backing run; back or backing weld

10 Fillet weld

11 Plug weld; plug or slot weld/USA

12 Spot weld

13 Seam weld

1.10.3 Table 2 - Supplementary Symbols

Shape of weld surface Symbol

a) Flat (usually finished flush)
b) Convex
c) Concave

1.11 Test questions

1. List main welding machine specifications?

2. Why edge preparation is important in welding process?
3. List main edge preparation methods?
4. What are the merits and demerits of AC and DC welding?
5. Why DC welding is preferred over AC welding?
6. How a welding is represented in drawing?
7. Draw any five welding symbols?

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CHAPTER 2

ARC AND GAS CUTTING

2.1 Objectives

 To understand arc and gas cutting methods

 To understand theory of cutting
 To familiarize attachments required for cutting process

2.2 Pedagogy

o Demonstration
o Use of smart classroom
o Practical class
o Gas welding workshop visit

2.3 Introduction

Metals both ferrous and non ferrous metals used for Industrial purpose are generally
available in forms of sheets, plate and rods of different cross sections. Lathe, shaper,
different types of sawing machines are used for cutting these metals in required shape
and size. But gas cutting and Arc cutting methods are used for cutting ferrous metals
more easily and quickly and known as thermal cutting.

2.4 Theory of gas cutting

The melting temperature of oxide of ferrous metals is well below the melting
temperature of ferrous metals. This theory is utilized in cutting process. When ferrous
metals are heated to red hot condition and exposed to pure oxygen, chemical reaction
happens between heated metal and oxygen (oxidation reaction ) producing a great
amount of heat. Due to low melting point of metal oxide it melts immediately and blown
away by oxygen stream.

2.4.1 Cutting operations

Following are the two steps involved in oxy acetylene gas cutting process:
Pre heating
Heating the metal before welding or cutting is known as pre heating. In oxy acetylene
gas cutting operation an oxy acetylene flame is used to preheat the metal to red hot
condition. It is about 9000C.

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Oxidation
A stream of high pressure oxygen is directed to the preheated metal. Chemical reaction
takes place between metal and oxygen to produce great amount of heat and melts the
metal.

2.4.2 Flame cutting Torch

Cutting torch and welding torches are different in construction. A separate oxygen
lever is provided excessive flow for oxygen for cutting process. Oxy –propane, oxygen-
LPG, oxy- hydrogen, combinations are also used .Cutting process using Oxy-acetylene
mixture is done at about 3200 degree centigrade.

Fig. 2.1 Flame cutting

torch
A cutting blow pipe has two control valves for oxygen and acetylene to control the
preheating flame. One high pressure leaver type control valve is provided to control
pure oxygen for making cutting.

The nozzle used in cutting torch has one hole in the centre for cutting oxygen and
number of holes around the circle for preheating flame.

2.4.3 Main accessories for gas cutting process

Cutting Torch, oxy-acetylene cylinders, pressure gauges, hose connections, spark

lighter, goggles, leather hand gloves& apron.

2.5 Mechanism of arc cutting

Cutting with the arc consists of melting and removing metal with the force of the arc.
Most type of metals can be cut with the arc, such as steel cast iron, alloys and non
ferrous metals. Rivets or bolts may be removed with the cutting action of electric arc.
Arc cutting is a different process from gas cutting or flame cutting. High ampere current
arc is used for cutting process and not based on any chemical process.

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2.6 Electrode for arc cutting

Arc welding equipment is also used for Arc cutting process. Straight polarity with
high ampere current is preferred for arc cutting Carbon may be the most economical
electrode for cutting job. But it can be only used with DC machines. The shielded
electrode may be used with both AC and DC machines. Arc cutting produce more
fumes and toxic gases so avoid cutting in confined areas.

Arc – air process or gauging process

This is similar method of arc cutting by using a carbon electrode. Metal is melted using
the heat of arc formed by the a carbon electrode and compressed air jet from a special
nozzle pushed the molten metal aside and cutting is done. Ferrous, non-ferrous and
alloys are using this cutting process. As compared to other methods, this method is
faster one by using 6-7 Kg/cm air is used for this purpose.

Oxy – arc cutting

Cutting process is done by the help of an oxygen jet followed by heating the surface by
using a metal electrode arc. A steel tube is an electrode in this process. Both AC and
DC used for this method. Regulated oxygen from oxygen cylinder allowed to flow
through the steel pipe for cutting. Holes are easily made by this method.

2.7 Test questions

1. What is the theory of gas cutting?

2. What are the operations involved in gas cutting?
3. How a gas cutting torch is differed from a gas welding torch?
4. What is the difference between a gas cutting nozzle and gas welding nozzle?
5. What is the mechanism of arc cutting?

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CHAPTER 3

WELDING OF VARIOUS METALS AND WELDING DEFECTS

3.1 Objectives

 To understand welding of ferrous and nonferrous metals

 To understand welding of alloys
 To familiarize various welding defects, casus and remedies

3.2 Pedagogy

o Demonstration
o Use of smart classroom
o Practical class

3.3 Introduction

Almost all metals are weldable. Different metals need different welding techniques
because metals act differently at high temperatures. Some metals are easy to weld
while others are not, but welding process varies for each metal. For obtaining good
results under various circumstances, proper welding procedure are used for various
metals and also proper shielding atmosphere, proper fluxing materials and filler metal is
desired.

3.4 Ferrous metals welding

3.4.1 Ingot iron & Wrought iron

Ingot iron has excellent welding characteristics and it can be welded by any of the
welding process. The law carbon content in the metal does not harden after welding.
Therefore heat treatment before or after welding is also not needed.

3.4.2 Low carbon steels (carbon up to0.30%)

These are easily welded by all the welding process and resultant welds and joints
are high quality.

3.4.3 Tool steels

Compared to other carbon steels, tool steels are more difficult to weld. Gas welding
and pressure gas welding processes are recommended for welding of tool steels. In gas

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welding, proper welding rods having such carbon content which will ensure the carbon
percentage of deposited metal at least equal to the base metal should be used. Proper
flux must be used for welding and pre-heat the steel and anneal after welding.

3.4.4 Cast iron

Carbon in iron is present in either free or chemically combined form. During welding
both free and combined carbon go into solution in the molten metal. If it is suddenly
cooled, a large amount of combined iron is retained which results in formation of hard
metal in the weld. To reduce this effect rate of cooling is reduced by preheating the cast
iron. Gas welding, arc welding using special electrodes carbon arc welding Thermite
welding, braze welding and brazing are generally used for cast iron welding.

3.4.5 Stainless steel

It can be welded satisfactorily by nearly all welding processes. Proper heat treatment
is needed after welding.

3.5 Non ferrous metals welding

3.5.1 Aluminium
Aluminum is not difficult to join but aluminum welding is a difficult process due to
following characteristics of aluminium.

Aluminum oxide surface coating.

High thermal conductivity.
High thermal expansion coefficient.
Low melting temperature.
The absence of color change as temperature approaches the melting point.

Aluminum is an active metal and it reacts with oxygen in the air to produce a thin
hard film of aluminum oxide on the surface. The melting point of aluminum oxide is
approximately 1926oC, which is almost three times the melting point of pure aluminum,
660oC. The aluminum oxide film must be removed by use of fluxes consisting of sodium
or potassium chloride. Oxy acetylene flame is suitable for welding aluminium. To avoid
oxide formation slightly carburizing flame is used for welding aluminium.

3.5.2 Copper
Copper alloys possess properties that require special attention when welding. These
are:
High thermal conductivity.
High thermal expansion coefficient.

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Relatively low melting point.

The molten metal is very fluid.
It has high electrical conductivity.

The oxides exists on copper may be removed by using warm solution of sulphuric
acid. A high capacity high efficiency DC welder capable of delivering uniform welding
current is used for welding copper.

3.6 Welding of alloys

3.6.1 Aluminium Alloys

Aluminium alloys are generally available in two forms, non-heat treatable and heat-
treatable. The heat of welding decreases the strength of both types of Aluminium alloys.
Therefore proper heat treatment process is very essential. Also the proper selection of
flux, filler metal and distortion care are equally important. Arc, gas, electric resistance,
brazing and soldering processes are used for welding of these alloys.

3.6.2 Copper alloys

These can be welded by most commonly used methods of gas welding, resistance
welding, brazing and soldering.

3.7 Welding defects

Common weld defects include:

1. Distortion
2. Lack of fusion
3. Lack of penetration
4. Porosity
5. Inclusions
6. Cracking
7. Undercut
8. Distortion

3.7.1Distortion

Any change that occurs during welding in the shape and size of the joining pieces is
known as distortion.

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Types
Longitudinal distortion – distortion in the direction of welding
Transverse distortion - distortion opposite to the direction of welding
Angular distortion – change in the angle at the place of joint

Fig.3.1 Welding Distortion

3.7.2 Lack of fusion

Fig. 3.2 Lack of Fusion

To achieve a good quality join it is essential that the fusion zone extends the full
thickness of the sheets being joined. Lack of fusion results from too little heat input and /
or too rapid traverse of the welding torch (gas or electric).

3.7.3 Lack of penetration

Fig. 3.3 Lack of Penitration

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Excess penetration arises from high heat input or slow movement of the welding
torch (gas or electric). Excess penetration - burning through - is more of a problem with
thin sheet as a higher level of skill is needed to balance heat input and torch traverse
when welding thin metal.

3.7.4 Porosity

Fig. 3.4 Porosity

This occurs when gases are trapped in the solidifying weld metal. These may arise
from dirt, oil or grease, on the metal in the vicinity of the weld. This can be avoided by
ensuring all consumables are stored in dry conditions and work is carefully cleaned and
degreased prior to welding.

3.7.5 Inclusions
These can occur when several runs are made along a V joint when joining thick
plate using flux cored or flux coated rods and the slag covering a run is not totally
removed after every run before the following run.

3.7.6 Cracking

Fig. 3.5 Cracking

This can occur due to thermal shrinkage or due to a combination of strain and phase
change. In the case of welded stiff frames, a combination of poor design and
inappropriate procedure may result in high residual stresses and cracking. To prevent
these problems a process of pre-heating in stages may be needed and after welding a
slow controlled post cooling in stages will be required.

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3.7.7 Undercutting

Fig. 3.6 Undercut

Undercutting is when the weld reduces the cross-sectional thickness of the base
metal, which reduces the strength of the weld and work pieces. One reason for this type
of defect is excessive current, causing the edges of the joint to melt and drain into the
weld.

3.8 Test questions

1. Write short notes on ferrous metal welding

2. Why aluminum welding process is more difficult than other metals welding?
3. Write short note on copper welding
4. What are the common welding defects?
5. What is distortion?
6. How porosity occurs in welded joints?
7. What is mean by inclusion welding defect?
8. How cracking happens in welded joint?
9. What is mean by undercutting?

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CHAPTER 4

SPECIAL WELDING PROCESSES AND ITS APPLICATIONS

4.1 Objectives

 To understand TIG and MIG welding process

 To understand Thermite welding process
 To understand different resistance welding processes
 To understand submersible arc welding process

4.2 Pedagogy

o Chart, Diagrams
o Use of smart classroom

4.3 Introduction

Apart from the welding processes explained earlier there are also a number of
special welding processes which are used for joining different types of metals more
quickly without any defects in mass production and in special purposes.

4.3.1 MIG welding

Fig. 4.1 MIG Welding

Metal inert gas welding is used for quality welded joints in ferrous, non ferrous and
alloys. A consumable Metal electrode is used in this welding process .This electrode is

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available in rolls. Welding is done by the arc between electrode and work. An Inert gas
shield provided at the, which makes a protective cover for molten metal. Argon, Helium,
Carbon dioxide and mixtures of these gases are used in MIG welding. Argon gas is
used for stain less steel and aluminum welding. Helium gas is used in copper welding.
Generally DC is used for MIG welding. High depositions of metals in joints, no need of
removing slag from joints are main advantages of this method. MIG welding is done by
automatic methods or manually.

4.4 TIG welding

Fig. 4.2 TIG Welding

TIG is short form of Tungsten Inert Gas welding. One non consumable Tungsten
electrode used for making arc for welding process and this arc is protected by a shield
of suitable inert gas, filler rods are used for welding if it is necessary. Over heating of
Tungsten electrode is controlled by water cooling.

TIG welding is called Argon gas welding if argon gas is used in this process. Both
AC &DC used for TIG welding.AC and argon gas is suitable for Aluminium welding. But
Helium gas is using copper welding. All metals from below 1mm to 10mm sheets are
easily welded this method without using any fluxes.

4.5 Thermite welding

Thermite welding is the only welding process employing an exothermal chemical

reaction (Thermite reaction) for the purpose of developing a high temperature. It is a
fusion process in which weld is affected by pouring super heated liquid Thermite steel
around the parts to be welded.

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Fig. 4.3 Thermit Welding

Preparation for a Thermite welding process is shown. A wax pattern is made around
the parts to be welded. Around this pattern a sheet box is placed and the space
between pattern is filled with refractory sand Thermite mixture (finely divided aluminum
and iron oxide) in the crucible is ignited , and super heated molten iron about 3000
degree centigrade is formed. This super heated iron is used for welding and slag of
aluminium oxide cover the molten metal.

4.6 Resistance welding

Heat is produced when current flows through a resistance. This principle is used
resistance welding. As per Jules law, heat produced when current flows between two
plates placed together as per formula I2RT and this heat used for welding process.

A low voltage AC is used for Resistance welding. A timer used to control the time of
current flow of this process.

Following are the main Resistance welding methods

4.6.1 Spot welding

It is done by clamping two or more pieces of metal in the form of sheet. To weld two
sheets, place these sheets between two welding electrodes, the electrodes tips are
made of copper, the welding current depends on the thickness and the composition of
the sheets.

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4.6.2 Seam welding

In this type of welding the overlapping sheets of metal are welded either along
continuous line by moving the sheets between the two electrodes wheel, through which
the welding current flows in short or long intervals.

Fig. 4.4 Spot Welding Fig.4.5 Seam Welding

4.6.3 Projection welding

In projection welding we use electrodes inside of pointer for the transfer of heat. The
heat is produce in both electrodes at the location where the welding is desired at the
same time. The projection welding is shown in the following figure.

4.6.4 Resistance Butt welding

In this welding, one bar is hold in fixed clamp and the other in moving clamp. The
two bars are brought together as shown in the figure. The heating (welding) current is
produced by the welding transformer. This type of welding is used to weld pips, wires
and railway tracks.

Fig. 4.6 Projection Welding Fig.4.7 Resistance Butt Welding

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4.7 Test questions

1. List different special welding techniques and its importance

2. With the help of simple sketch explain MIG welding
3. With the help of simple sketch explain TIG welding
4. Differentiate between MIG and TIG welding
5. What is Thermite welding? How it is done?
6. What is mean by resistance welding?
7. List different types of resistance welding techniques

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Block II
WORKSHOP PRACTICE

Note: The various steps involved in conducting and recording exercise 1 is described.
For the rest of the exercise, those steps have to be written by the students after
learning the concepts presented in Block 1.

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EXERCISE 1: STRAIGHT LINE DEPOSITING - VERTICAL

Date :

All Dimensions are in mm

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EXERCISE 1: STRAIGHT LINE DEPOSITING - VERTICAL

Date:

Aim: To make a vertical straight line welding on MS Flat.

Materials Required: 100*40*6 mm MS Flat, Electrode 10SWG(3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning,

Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS Flat by using hacksaw.

2. File the edge of work piece to the correct dimensions using a flat file.

3. Mark a straight line on the work piece as per dimensions.

4. Place the work piece on the worktable in vertical position

5. Check for the earth connection and hold the electrode on the electrode holder.

6. Adjust the output current of the transformer and switch it ON.

7. Check the arc by welding a waste metal piece.

8. Do the first run of welding from bottom end to top end on the marked line of

workpiece.

9. After cooling, remove the slag from the weld surface using a chipping hammer

and wire brush.

10. Do the second run of welding if required and clean the surface.

Result:
Vertical Straight line welding is obtained.

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EXERCISE 2: SQUARE BUTT JOINT - VERTICAL

Date :

All Dimensions are in mm

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EXERCISE 2: SQUARE BUTT JOINT - VERTICAL

Date:

Aim: To make a vertical square butt joint.

Materials Required: 205*40*6 mm MS Flat, Electrode 10SWG (3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning and

Tacking, Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS Flat by using hacksaw.

2. File the edges of the work pieces to the correct dimensions using a flat file for a

square butt joint.

3. Check for the earth connection and hold the electrode on the electrode holder.

4. Adjust the output current of the transformer and switch it ON.

5. Check the arc by welding a waste metal piece.

6. Place the work pieces on the worktable and tack them.

7. Place the work piece on the worktable in vertical position.

8. Do the first run of welding from bottom end to top end of the joint.

9. After cooling, remove the slag from the weld surface using a chipping hammer

and wire brush.

10. Do the second run of welding if required and clean the surface.

Result: Vertical Square butt joint is obtained.

SITTTR, Kalamassery Page 26
 Welding

EXERCISE 3: SINGLE ‘V’ BUTT JOINT - VERTICAL

Date :

All Dimensions are in mm

SITTTR, Kalamassery Page 27

 Welding

EXERCISE 3: SINGLE ‘V’ BUTT JOINT - VERTICAL

Date:

Aim: To make a vertical single V butt joint.

Materials Required: 205*40*6 mm MS Flat, Electrode 10SWG (3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning and

Tacking, Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS Flat by using hacksaw.

2. File the edges of the work pieces to the correct dimensions using a flat file for a V

joint.

3. Check for the earth connection and hold the electrode on the electrode holder.

4. Adjust the output current of the transformer and switch it ON.

5. Check the arc by welding a waste metal piece.

6. Place the work pieces on the worktable and tack them.

7. Place the work piece on the worktable in vertical position.

8. Do the first run of welding from bottom end to top end of the joint.

9. After cooling, remove the slag from the weld surface using a chipping hammer

and wire brush.

10. Do the second run of welding if required and clean the surface.

Result:

Vertical single V butt joint is obtained.

SITTTR, Kalamassery Page 28

 Welding

EXERCISE 4: ‘T’ JOINT - VERTICAL

Date :

All Dimensions are in mm

SITTTR, Kalamassery Page 29

 Welding

EXERCISE 4: ‘T’ JOINT - VERTICAL

Date:

Aim: To make a vertical T joint.

Materials Required: 205*40*6 mm MS Flat, Electrode 10SWG(3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning and

Tacking, Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS Flat by using hacksaw.

2. File the edges of the work pieces to the correct dimensions using a flat file for a T

joint.

3. Check for the earth connection and hold the electrode on the electrode holder.

4. Adjust the output current of the transformer and switch it ON.

5. Check the arc by welding a waste metal piece.

6. Place the work pieces on the worktable and tack them.

7. Place the work piece on the worktable in vertical position.

8. Do the first run of welding from bottom end to top end of the joint.

9. After cooling, remove the slag from the weld surface using a chipping hammer

and wire brush.

10. Do the second run of welding if required and clean the surface.

Result:

Vertical T joint is obtained.

SITTTR, Kalamassery Page 30
 Welding

EXERCISE 5: STRAIGHT LINE DEPOSITING - OVER HEAD

Date :

All Dimensions are in mm

SITTTR, Kalamassery Page 31

 Welding

EXERCISE 5: STRAIGHT LINE DEPOSITING - OVER HEAD

Date:

Aim: To make a over head straight line welding on MS Flat.

Materials Required: 100*40*6 mm MS Flat, Electrode 10SWG (3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning,

Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS Flat by using hacksaw.

2. File the edge of work piece to the correct dimensions using a flat file.

3. Mark a straight line on the work piece as per dimensions.

4. Place the work piece on the worktable in over head position

5. Check for the earth connection and hold the electrode on the electrode holder.

6. Adjust the output current of the transformer and switch it ON.

7. Check the arc by welding a waste metal piece.

8. Do the first run of welding from bottom end to top end on the marked line of work

piece.

9. After cooling, remove the slag from the weld surface using a chipping hammer

and wire brush.

10. Do the second run of welding if required and clean the surface.

Result:
Over head Straight line welding is obtained.

SITTTR, Kalamassery Page 32

 Welding

EXERCISE 6: SQUARE BUTT JOINT - OVER HEAD

Date :

All Dimensions are in mm

SITTTR, Kalamassery Page 33

 Welding

EXERCISE 6: SQUARE BUTT JOINT - OVER HEAD

Date:

Aim: To make an over head square butt joint.

Materials Required: 205*40*6 mm MS Flat, Electrode 10SWG (3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning and

Tacking, Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS Flat by using hacksaw.

2. File the edges of the work pieces to the correct dimensions using a flat file for a

square butt joint.

3. Check for the earth connection and hold the electrode on the electrode holder.

4. Adjust the output current of the transformer and switch it ON.

5. Check the arc by welding a waste metal piece.

6. Place the work pieces on the worktable and tack them.

7. Place the work piece on the worktable in over head position.

8. Do the first run of welding from bottom end to top end of the joint.

9. After cooling, remove the slag from the weld surface using a chipping hammer

and wire brush.

10. Do the second run of welding if required and clean the surface.

Result:
Over head Square butt joint is obtained.
SITTTR, Kalamassery Page 34
 Welding

EXERCISE 7: ROUND FILLET WELDING

Date :

All Dimensions are in mm

SITTTR, Kalamassery Page 35

 Welding

EXERCISE 7: ROUND FILLET WELDING

Date:

Aim: To make a round fillet welding.

Materials required: 40*40*6 mm MS Flat, 25mm dia*25 MS rod, Electrode 10SWG

(3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning and

Tacking, Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS Flat and MS rod by using hacksaw.

2. File the edges of the work pieces to the correct dimensions using a flat file for a

round fillet joint.

3. Check for the earth connection and hold the electrode on the electrode holder.

4. Adjust the output current of the transformer and switch it ON.

5. Check the arc by welding a waste metal piece.

6. Place the work pieces on the worktable and tack them.

7. Place the work piece on the work table.

8. Do the first run of welding of the joint.

9. After cooling, remove the slag from the weld surface using a chipping hammer

and wire brush.

10. Do the second run of welding if required and clean the surface.

Result:
Round fillet joint is obtained.
SITTTR, Kalamassery Page 36
 Welding

EXERCISE 8: SHAFT BUTT JOINT

Date :

All Dimensions are in mm

SITTTR, Kalamassery Page 37

 Welding

EXERCISE 8: SHAFT BUTT JOINT

Date:

Aim: To make a shaft butt joint.

Materials required: 50mm dia*153 MS rod, Electrode 10SWG (3.2mm) MS

Tools and equipment Required: Steel Rule, Try Square, Hacksaw, Flat File, Welding
Shield, Chipping Hammer, Wire Brush, Gloves, Flat tongs, Bench vice, Welding
Transformer unit.

Operations to be carried out: Measuring, Marking, Cutting, Filing, positioning and

Tacking, Welding, Chipping and cleaning.

Procedure:

1. Check, Mark and cut the required size of MS rod by using hacksaw.
2. File the edges of the work pieces to the correct dimensions using a flat file for a
shaft butt joint.
3. Check for the earth connection and hold the electrode on the electrode holder.
4. Adjust the output current of the transformer and switch it ON.
5. Check the arc by welding a waste metal piece.
6. Place the work pieces on the worktable and tack them.
7. Place the work piece on the work table.
8. Do the first run of welding of the joint from bottom to top.
9. Rotate the work piece and do the same on the other side.
10. After cooling, remove the slag from the weld surface using a chipping hammer
and wire brush.
11. Do the second run of welding if required and clean the surface.
Result:
Shaft butt joint is obtained.

SITTTR, Kalamassery Page 38