Manufacturing Practice - Lab Manual - B.Tech. - Mechanical Engineering

Manufacturing Practice (ME-104)
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B. TECH. –1st / 2nd SEMESTER

Prepared by: Harlal Singh Mali

Date: 10 July 2006

Reviewed by: Harlal Singh Mali

Date: 04 Aug 2009

Approved by: …………

Date: ……………

CIET/ISO/ME (LAB)/014

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Chandigarh- Patiala National Highway, Teh.- Rajpura. Distt. Patiala- 140401

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ME-104
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MANUFACTURING PRACTICE
Maximum Marks: 100
Internal :
40
External:
60

PART-A
1.

2.

3.
4.

CARPENTRY AND PATTERN MAKING :
Various types of timber and practice
boards, defects in timber, seasoning of wood; tools, wood operation and various joints;
exercises involving use of important carpentry tools to practice various operations and
making joints.
FOUNDRY SHOP Introduction to moulding materials; moulds; use of cores; melting
furnaces; tools and equipment used in foundry shops; firing of a cupola furnace; exercises
involving preparation of small sand moulds and castings.
FORGING PRACTICE:
Introduction to forging tools; equipments and operations;
forgability of metals; exercises on simple smithy; forging exercises.
MACHINE SHOP
machines, grinders etc; cutting tools and operations; exercises
involving awareness.

PART-B
5.

6.

7.

8.

WELDING SHOP: Introduction to different welding methods; welding equipment;
electrodes; welding joints; welding defects; exercises involving use of gas/electric arc
welding.
ELECTRICAL & ELECTRONICS SHOP Introduction to electrical wiring; preparation of
PCBs involving soldering applied to electrical and electronic applications; exercises
preparation of PCBs involving soldering applied to electrical and electronic applications.
SHEET METAL:
Shop development of surfaces of various objects; sheet metal forming
and joining operations, joints, soldering and brazing; exercises involving use of sheet metal
forming operations for small joints.
FITTING SHOP
Introduction of fitting practice and tools used in fitting shop; exercise
involving marking, cutting, fitting practice (Right Angles), male- Female mating parts
practice, trapping practice.

TEXT BOOKS
1. Raghuwanshi, B.S. ; A course in Workshop technology, Vol 1 & II, Dhanpat Rai & Sons ,
New Delhi.
2. Jain, R.K. ; Production Technology, Khanna Publishers, New Delhi.
3. Singh, S, ; Manufacturing Practice, S.K. Kataria & Sons, New Delhi

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CARPENTRY SHOP
SYLLABUS
Various types of timber and practice boards, defects in timber, seasoning of wood; tools, wood
operation and various joints; exercises involving use of important carpentry tools to practice various
operations and making joints.

Instructor Incharge : Mr. Rajinder Singh

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SAFETY PRECAUTIONS
CARPENTRY SHOP
1. While working keep your mind & eyes on the job & do not
indulge in talking.
2. Avoid using loose clothing.
3. There should be no sharp tools in your pocket.
4. The tools being used should be well sharpened.
5. The floor of the shop should be well cleaned, free from scrap &
wooden pieces carrying nails etc.
6. Safety guard provide on the machines should be in proper
position & well secured.
7. Safety guard provide on the machines should be in proper
position & well secured.
8. While working on a band saw it should be ensured that the
guides are properly adjusted.
9. Feed the stock directly the moving hand & don’t press from sides
10. Cutting should be start only after the saw attains the full Speed.
11. Turning tools should be held firmly.
12. use goggles while turning & sawing.

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INTRODUCTION:
In carpentry workshop, wooden pieces of commercial sizes are given specific shape and size, as per
the requirements. The processes involved in carpentry shop are making layout, marking, sowing,
plaining, chiseling jointing etc.
In this chapter we shall study about the raw material and tools used in carpentry shop various raw
material used that shop are wood, nut, screw, nut and bolt and glue etc. The tools are classified as
marking, cutting, planning, chiseling, striking etc.
VARIOUS TYPES OF TIMBER AND PRACTICE BOARDS

Types of Wood – Common wood are generally classified according to their degree of hardness of
softness.
1.

Hardwood- Hard wood has closed structure, heavy in weight, dark in colour and is difficult
to work on it, annual rings are not distinct and good tensile strength.

2.

Soft Wood- Hard wood has less weight, less durable and is easy to work out. Soft wood
catches fire soon as compared to hardwood, annual rings are quite distinct.

3.

Plywood: It consists of more than three layers. Middle layer is called care which is thick and
not of good quality. The top and bottom are called as face plys which is glued on the care at
top and bottom. The grains of adjacent layers are kept perpendicular to each other which
prevents plywood form warpage.

Types of Ply – Ply Board, Comarcal Board, Chip Board, Soft Board.
Advantage of Ply od
1.

Lighter in weight and easy to work.

2.

Can be used for decorating the furniture as well as houses.

3.

It is also available in bigger sizes.

4.

Possesses bottom strength then solid wood of same thickness.

DEFECTS IN TIMBER
Following are the common defects occurring in the wood and it can be divided into following three
categories.
1.

Natural Defects are the defects which are caused in the tree due to abnormality in the grouts.

2.

Defects are also caused during seasoning operation.

3.

Some defects are also there due to termites or insects.

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Natural defects – Wood being a product of nature is subjected of natural defects, some of them are
explained below:
1.

Shakes: Shakes are caused due to the separation of wood grains, some times, burning of
tissues and shrinkage of interior parts takes place which causes radial or circular rupture in
tissues and creates cavities, which are called shakes are of three types
(i)

(ii)

Wind shakes or Cup shaker: The separation of annual rings is called wind shake or
cup shake. These defects are common in lines.

(iii)

2.

Heart and star shakes: These defects in the heart wood in other older tree,
especially. Hemlock heart shakes can be evidenced by a small point cavity at the
center of the wood as shown in fig.

Radial Shakes: Radial shakes are the radial splits extending from bark towards the
center. These cracks over the cross section of the log are winder at the bark and
narrow down near the center as shown in fig.

Knots: Knot represent irregular in the body of a tree which interrupt the smooth course of the
grand. The fibers of the tree are turned from their normal shaped and grow around the knot at
that point of a tree where a link is being formed. Knots are two types:
(i) Dead knots: When the separation of benches or hurbs takes place before the tree is cut,
the knot thus formed called leaf knot. This knot is not held firmly and wood having leaf knot
is not recommended for engineering purposes.
(ii) Live knots: If the separation occurs after falling of a tree the knot thus formed is called
live knot. A wood having live knot can be used for engineering purposes. According to the
shapes knot can be classified as shown in fig.

SEASONING OF WOOD
The process of removing moisture from freshly cut down trees is known as seasoning In these threes
the percentage of moisture is very high. The wood uses of engineering purposes containing high
percentage of moisture may cause many types of problems, such as shrinkage, warpage distortion
etc. To a point this, seasoning is done. After seasoning the percentage of moisture is reduced to 1020%.

Types of Seasoning
(i)

Air Seasoning: In this method, the timber balks are stacked in a sheet such that they
are not directly exposed to sun and rain but a free circulation of air takes place
through them. The timber balks are allowed to remain in that condition for a long
times. The balks be periodically turned upside which accelerates the rate of drying.
Due to the circulation of free air through the stack, the excess moisture evaporates
and the wood gets seasoned.
This is the commonly used method which takes much time but proper seasoning can
be easily done with a little care.

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(ii)

Water Seasoning: In this method, timber balks are immersed in flowing water for a
fortnight. The flowing stream of water removes the sap. The timber is then taken out
and air seasoning is done as usual. This method takes less time but the strength of
wood reduced.

(iii)

Artificial or Kiln Seasoning: This is a quick process of seasoning of this method,
the timber balks are stacked and over large trollies which are then driven into hot
chambers or kilus. Hot air or dry stem is pushed into the chamber under controlled
temperature conditions. The moisture content is reduced because the evaporation
takes place and ultimately the timber gets seasoned.

CARPENTRY HAND TOOLS
Carpentry tools:
The efficiency of the workman depends upon the tools used in the workshop. Good quality tools
always makes the work easy. In the carpentry shop the tools are classified as under:
Measuring Tools
(a)

Four Fold box wood rule: It is generally 2 feet long and is folded from three places. It is
marked with inch and millimeter scale.

(b)

Steel rule: It is made up of stainless steel and is marked with scale.

(c)

Inch tape: It is made up of flexible thin steel strip. It is folded around a center pin attached
with a small handle. It is graduated.

Marking Tools
(a)

Pencil: Lead pencil is generally used for marking purposes.

(b)

Scriber: Scriber has a sharp conical edge used to mark on even hard surfaces. The front edge
is hardened so as to resist wear and tear. It is made up of carbon steel.

(c)

Marking gauge: It is used to draw parallel lines. The movable portion of the gauge is
adjusted to suitable position and is tightened on to stem.

(d)

Try square: It is used to draw parallel lives at right angles, parallel or to check the trueness
of planed surfaces. It is made up of a steel blade with heavy base.

(e)

Bevel square: It consists of wooden handle fitted with an adjustable handle blade. The blade
can be rotated by 180º w.r.t. handle. It is used for marking various angles.

(f)

Compass/Dividers: These are used for dividing equal number of parts and for drawing arcs
and circles. It consists of two legs with a spring on the top of the legs. A screw is also
attached at the center of the legs for adjustment.

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Cutting Tools:
Saw and chisel are used as cutting tools in carpentry shop.
Saw: A saw is a multi tooth tool made up of thin sheet attached with a wooden handle. Its teeth are
ground and sharpened to achieve smooth cutting. Different types of saw are:
(i)

Rip Saw: It is hand saw from 30 cm to 75 cm long, containing one to one and half teeth per
cm. It should not be called a hand saw but a rip saw only.

(ii)

Tenon saw: It derives its name from the tenon form of joint It is a thin saw ranging from 20
cm to 40 cm in length, and is supported by back of wrough iron or brass; hence it is also
called a back saw. It contains about 4 teeth at a cam.

(iii)

Coping Saw: It is used for cutting quick or sharp curves either internal or external.

(iv)

Compass Saw: It is a short narrow saw, tapering towards the point, used for cutting sweeps
and large interior curves by hand sometimes termed as a table saw.

(v)

Keyhole or Pad saw: It is used for cutting thick internal curves where it is impossible to use
other saws.

(vi)

Cross-cut saw: It is a saw provided with two handles, one at each end used for cutting heavy
timber across the grains.

(vii)

Bow saw: It consists of a wooden frame, a bar, a string, lever and two handles. It is used to
produce curved surfaces with quick turns. The blade is tightened with the help of string and
lever.

Setting of saw teeth: The teeth of saw are bend in opposite direction alternatively. It is used as saw
teeth setting. It is made to form a clearance between two cutting edges so that the saw may work
without any restriction.
Chipping Tools:
Chisel : There are three types of chisels commonly used in carpentry shop:
(i)

Firmer Chisels: It is a general chisel used to finish inside grooves. It has various
sizes of cutting edge depending upon the work to be done. Width varies from 5 mm to
35 mm.

(ii)

Mortise Chisel : It is used to make mortises. Mortise chisel is used for heavy cuts.
The blade thickness varies from 5 mm to 12 mm.

(iii)

Gauge Chisel : It is used to finish curved holes. Gauge chisels are of two types i.e.
inside and outside.

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Planning Tools
(i)

Planes: Planning tools are used for smoothening purposes. Preparing proper sizes and
for forming curved wooden strips. Many types of planes are used in carpentry shop

(a)

Trying plane: Trying plane is 18” long and used for general purpose planning of
wood. It is applied after jack plane.

(b)
(c)

(e)
(f)
(g)

Jack plane: Jack plane is 10”-14” long. Heavy and is used for rough cutting.
Smoothing plane: Smoothing plane is used for finishing work. It is small in size
generally 9” long.
Rebate plane: Rebate planes are used for preparing household goods are furniture
plough plane is used for making grooves.
Moulding plane
Plough plane
Hollow plane: Hollow planes are used for producing curved grooves.

(h)

Spoke shave: Spoke shave is also used for shaving corners.

(ii)

Rasp cut file : It is also known as a rasp file. It is a finishing tool used to make the
wood surface smooth, remove sharp edge. Finishing fillers are other interior surfaces.
Sharp cutting teeth are provided on its surface for this purpose. This file is used in
wood work only.

(d)

Striking Tools: Striking tools are used to force the nails or chisels into the wood. Main striking tools
are as under:
(i)
Cross Peen Hammer: It has a cast steel body and a wooden handle. Body has two
parts face and pean. In cross pean hammer, the pean is in the form of a narrow, round edge
ridge placed at right angle to the axis of the handle.
(ii)
Claw Hammer: It is used for striking as well as for pulling the nails from the wood.
The material of the wood is cast steel, one end is made striking and the second is claw face.
(iii) Mallet: It is used to strike the chisels which have wooden handles. It is made up of a
hard wood and is round or rectangular in shape.
Sharpening Tool:
Water Stone: It is a rectangular piece of stone generally kept in a wooden base. It is used to
re-sharpen the chisels, bits, plane blades and other tools, white sharpening water is sprinkled
on the stone.

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Objective:

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To Prepare a “T – LAP JOINT” as per sketch.

Tools Used: Steel Rule, Pencil, Try square, Marking Gauge, Rip saw and Tenon saw, Jack Plane
and Smooth Plane, Firmer Chisel, Mallet and Ball peen Hammer
Material Used: Wooden piece of “RED MARINDI”’Nails and fevicol.
Drawing: - See Diagrams

Procedure:1. Taken a wooden piece slightly more than given dimension.
2. Fix the job piece in carpentry vice and do planning on width side the help of jack plane and
smoothing with the smooth plane and check flatness and straightness of the work piece with the
help of try square.
3. Same pervious process repeat on adjacent side upto make right angle (i.e. 900 ).
4. Make one size (i.e. 30 mm or 40 mm) on the work piece and remove extra material accordingly
with the help of marking gauge, jack plane and smoothing plane.
5. Mark other size (i.e. 30 mm or 40 mm) on the job piece and remove extra material.
6. Mark two pieces each 150 mm in length with the help of pencil, try square and rip saw.
7. Mark on the both job piece as per given dimensions with the help of pencil, try square and
marking gauge.
8. Remove extra material and produce recess on one work piece at one end and middle of the
other job work as per given sketch with the help of rip saw and Tenon saw, firmer chisel and
mallet.
9. Fit the job pieces in the shape of “T=- LAP JOINT”

Safety Precautions
1.
2.
3.
4.

Never feed the stock faster than its capacity.
Hold the job firmly with clamping devices while working at the machines.
Always keep the tools at proper position when not in use. They should not be scrapped on the
wood floor.
Keep the floor area free from obstructions.

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HALF LAP T-JOINT

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Objective: To prepare a “Cross Lap Joint” as per given sketch.
Tools Used: Steel Rule, Pencil, Try square, Marking Gauge, Rip saw and Tenon saw, Jack Plane
and Smooth Plane, Firmer Chisel, Mallet and Ball pen Hammer
Material Used:

Wooden piece of “RED MARINDI”

Procedure:1.

Taken a wooden piece slightly more than given dimension.

2.

Fix the job piece in carpentry vice and do planning on width side the help of jack plane and
smoothing with the smooth plane and check flatness and straightness of the work piece with
the help of try square.

3.

Same pervious process repeat on adjacent side upto make right angle (i.e. 900 ).

4.

Make one size (i.e. 30 mm or 40 mm) on the work piece and remove extra material
accordingly with the help of marking gauge, jack plane and smoothing plane.

5.

Mark other size (i.e. 30 mm or 40 mm) on the job piece and remove extra material.

6.

Mark two pieces each 150 mm in length with the help of pencil, try square and rip saw.

7.

Mark on the both job piece as per given dimensions with the help of pencil, try square and
marking gauge.

8.

Remove extra material and produce recess on the middle of the both work piece as per given
diagram with the help of Rip saw, firmer chisel and mallet.

9.

Fit the job pieces in the shape of “CROSS LAP JOINT”

Safety Precautions
1.
2.
3.
4.

wood floor.

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HALF LAP CROSS JOINT

ALL DIMENSIONS ARE IN mm.

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Objectives:

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To prepare Mortise and Tenon Joint

Tools Used: Steel ruler, Try square, Measuring tape, Smoothing plane, Mortise and marking
gauge, Rip and Tenon saw, Pencil, Mallet, Ball Peen hammer, Clamping vice, Mortise, Gauge, and
firmer chisel
Materials Used:

wood Piece of require dimension

Procedure:
1.

Procure mortise and Tenon members of required dimension.

2.

Square the piece to the suitable dimension and mark their faces.

3.

Now, mark the length of the Tenon, and square a line all around it end at the point, which is
the shoulder. Also mark the width of the Tenon member on the mortise at the point where
they are jointed.

4.

Now use a mortises gauge, mark the thickness of the Tenon. Also. Mark width of the
mortises groove on the mortises member (for the face of the members that are to be flushed).
Using the same gauge.

5.

In order to avoid tearing of mortises while chiseling. Layout an additional check cut at both
Tenon and mortises members.

6.

Saw off the thin pieces of wood along the layout lines already marked, by using Tenon saw
or rip saw.

7.

Then trim off any unevenness with a sharp chisel.

8.

When working on a plane it should be ensured that the blades are sharp and the cut is light.
Use a push block for all face planning, especially on the short pieces of stock.

Safety Precautions
1.
2.
3.

wood floor.

4.


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TO PREPARE MORTISE & TENON JOINT

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Objective : To make C.I. bracket pattern wooden.
Tools used : Try square, steel rule, marking gauge, smoothing plane, flat file, dividers, Hand saw,
sand paper (soft wood)
Material : Partal 140 mm × 75 mm × 35 mm
Drawing : See diagram
Procedure :
1.
2.
3.
4.
5.
6.
7.

Prepare the layout for C.I. bracket as per drawing.
Take all the allowances and core prints on the job.
Mark out the job as per the patterns layout.
Cut with handsaw and plane with the jack plane as per marking done as per layout.
Finish the C.I. bracket with the help of rasp file as per dimensions.
Check all the dimensions as per drawing.
Finally use sand paper to give smooth finish to C.I. bracket pattern.

Safety Precautions
1.
2.
3.
4.

wood floor.

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Objective : To make V Block Pattern to be used in foundry shop.
Tools used : Try square, steel rule, marking gauge, smoothing plane, flat file, dividers, Hand saw,
sand paper (soft wood)
Material : 100 mm × 55 mm × 55 mm
Drawing : See diagram
Procedure :
1.
2.
3.
4.
5.
6.
7.

Prepare the layout of V block pattern as per drawing.
Take all the allowances and core prints on the job.
Mark out the job as per the patterns layout.
Cut with handsaw and plane with the jack plane as per marking done as per layout.
Finish the V block pattern with the help of rasp file as per dimensions.
Check the dimensions as per drawing.
Finally use sand paper to give smooth finish to C.I. bracket pattern.

Safety Precautions
1.
2.
3.
4.

wood floor.

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FOUNDRY SHOP

SYLLABUS

Introduction to moulding materials; moulds; use of cores; melting furnaces; tools and equipment
used in foundry shops; firing of a cupola furnace; exercises involving preparation of small sand
moulds and castings.

Instructor In charge: Mr. Sukhdev Singh

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SAFETY PRECOUTION
FOUNDRY SHOP

1.
2.
3.
4.

Do not wear loose clothes.
Remove wrist watches, ring bracelets etc.
Wear goggles or a faces shield during pouring operation.
Hot metals should be kept away from body at a place where
there is no danger of body contact by any person.
5. Grasp the ladle firmly & be sure it is well balanced while
transporting molten metal.
6. Handel hot pieces with tong.
7. keep a clear space around the pouring area.
8. Do not tough a casting immediately after removing from mould.
9. Wear proper tools while working in the pouring area.
10. the shop should be properly lighted & ventilated to avoid
accident.
11. The moulding boxes should be properly lighted & ventilated
to avoid bursting.
12. Switch off the electric grinder after use & do not place it not
places it on floor while in operation.
13. If you see any accident happing you immediately inform the
instructor.

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FOUNDRY SHOP
INTRODUCTION:
FOUDRIES: The plant where jobs are prepared by melting and pouring the molten metals in to
moulds are known as foundries.
MOULD: A mould is a cavity so prepared that it can be used to make casting by molten metal into
it.
PATTERN: Pattern is a facsimile model of anything, which is used to prepare moulds by placing it
in sand.
CASTING PROCESS: The process of poring molten metal in to a predefined cavity of a mould and
allowing it to cool is known as casting process.
CASTINGS: The products made by casting process are known as castings.
HAND TOOLS
1.

SHOWEL: It consist of a iron pan with a wooden handle it can be used for mixing and
conditioning the sand and then transferring the mixture in some container

2.

TROWELS: These are used for finishing flat surface and corner in side a mould. Common
shapes of trowels.

3.

LIFTER: A lifter is a finishing tool used for repairing the mould and finishing the mould
sand. Lifter is also used for removing loose sand from mould.

4.

HAND RIDDEL: It is used for ridding of sand to remove foreign material from it. It consist
of a wooden frame fitted with a screen of standard wire mesh at the bottom.

5.

STRIKE OF BARE: It is a flat bar made of wood or iron to strike off the excess sand from
the top of a box after riming

6.

VENT WIRE: It is a thin steel rod or wire carrying a pointed edge at one and a wooden
handle or a bent loop at the other. after ramming and striking of the excess sand it is used to
make small holes called vents in the sand mold to allow the exit of gasses and steam during
casting.

7.

DRAW SPIKE: It is a tapered steel rod having a loop or ring at it is one end and a sharp
point at the other it is used to tap and draw patterns from the mould.

8.

RAMMER: Rammer are used for striking the sand mass in the molding box to pack it
closely around one pattern.
a)
b)
c)

peen rammer
floor rammer
hand rammer

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9.

SLICKS: The are used for repairing and finishing the mould surfaces and edges after the
pattern has been withdrawn the commonly used slices are heart and leaf square and heart
spoon and bead and heart and spoon.

10.

SMOOTHER AND CORNER SLICKS: they are also finishing flat and round surfaces
round or square corners and edges.

11.

SWAB: It is a hemp fiber brush used for moistening the edges of sand mould which are in
contact with the pattern surfaces before withdrawing the pattern it is also used for coating the
liquid blocking on the mould faces in dry sand moulds.

12.

SQRUE PIN: It is a tapered rod of wood or iron which is embedded in the sand and later
withdrawn to produce a hole called runner through which the molten metal is poured into the
mould.

13.

Bellow; it used to blow but the loose or unwanted sand from the surface and cavity of the
mould.

14.

DRAW SCREWS AND RAPPING PLATE : It is a long mild steel rod with a ring in one
end and threaded at the other, there is a plate known as rapping plate consisting of several
tapped holes.

15.

MOULDING BOXES : The moulding boxes or flasks used in sand moulding are of two
types;
(a)
(b)

16.

Closed moulding boxes.
Open type of snap flasks.

LADLES : They are used to receive molten metal from the melting furnace and pour the
same into the mould. their size is designated by their metal holding capacity. Small hand
shank ladles, used by a single. Moulder, are provided with only one handle and are made in
different capacities upto a maximum of 20kg.

CRUCIBLES : They are made of refractory material and are similar in shape to the ladles .They
are used as metal melting pots. The raw material or charge is broken into small pieces and placed in
them. They are then placed in crucible or pit furnaces which are coke fired.

PATTERN MATERIALS
1.
2.
3.
4.
5.
6

Wood.
Iron.
Aluminium;brass;zinc etc.
Plaster .
Plastic.
ax.

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TYPES OF PATTERNS
1. Solid or single piece pattern.
2. Two-piece or split pattern.
3. Multipiece pattern.
4. Match plate pattern.
5. Gated pattern.
6. Skeleton pattern.
7. Sweep pattern .
8. Pattern with loose pieces.
9. Cope and drag pattern.
10. Follow board pattern.
11. Segmental pattern.
MOULDING PROCESSES:
1.

MOULDING PROCESSES:
a)
b)
c)
d)

2.

Floor moulding.
bench moulding
pit moulding
machine moulding

ACCORDING TO THE MOULD MATERIALS
i)

Sand moulding
a)
b)
c)
d)
e)
f)
g)

Green sand moulding
Dry sand moulding
Core sand moulding
Cement bonded sand moulding
Shell moulding
Skin dried sand moulding
loam moulding

ii)

plaster moulding

iii)

Metallic moulding

CASTING PROCESSES
1.
2.
3.
a)
b)
c)

sand mould casting
plaster mould casting
metallic mould casting
gravity or permanent mould casting
slush casting
pressed casting

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d)
4.
5.
6.
7.

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die casting
centrifugal casting
precision casting
CO2 mould casting
continues casting

MOULDING SAND
Moulding sand is one of the most important and materials in production of sand casting. Sand is
formed by breaking up of rocks due to natural forces such as frost wind, rain and action of water.
a. Natural sand
b. Synthetic sand

TYPES OF SAND USED IN MOULDES
1.
2.
3.
4.
5.
6.
7.
8.
9.

Dry sand
Green sand
Loam sand
facing sand
Parting sand
Backing sand
Core sand
Oil sand
Molasses sand

COMPOSITION OF GREEN SAND
1.
2.
3.
4.

Silica sand
Coal dust
Bentonite sand
Water

75%
8%
12%
5 to 6%

PROPERTIES OF MOULDING SAND
1.
2.
3.
4.
5.
6.
7.

Porosity and permeability
Refractoriness
Adhesiveness
cohesiveness
Chemical resistance
plasticity
Moisture

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MAIN CONSTITUENT OF MOULDING SAND
The principal constituents of moulding sand are
1.
2.
3.
4.

Silica sand
Binder
Additives
Water

BINDERS
The purpose of adding to the binder to the moulding sand is to impart it sufficient strength &
cohesiveness so to enable it to retain its shape after the mould has been rammed & the pattern with
drawn. However it produce an obverse effect on the permeability of the sand mould.
The common binders used in foundry can be grouped as:
1.
2.

Organic binders
in organic binders

(ORGANIC)
1.
2.
3.
4.
5.
6.

Dextrin
Linseed oil
Molasses
Certain binders
Pitch
Resins, phenol formaldehydes

(INORGANIC)
1.
2.
3.
4.
5.
6.

Bentonite.
Kaolinite.
Limonite.
Ball clay.
Fire clay
Fullers earth

CORES: Core is a mass of sand that is put into the mould of from holes and cavities in the casting
cores are prepared separately in core box.
a)

HORIZONTAL CORE: It is the most common and simple type of core. It is assembled into
the mould with its axis horizontal. It is supported in the mould at its both ends.

b)

VERTICAL CORE: It is quit similar to a horizontal core except that it is fitted in the mould
with its axis vertical.

c)

BALANCED CORE: It is used to produce a blind holes along a horizontal axis in a casting.
As a matter of fact it is nothing but a horizontal core with the exception that it is supported
only one end the other end remaining free in the mould cavity.

d)

HANGING OR CIVER CORE: A core which hangs vertically in the mould and has no
support at is bottom is known as a hanging core. In such a case it is obvious that the entire
mould cavity will be contained in the drag only.

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CORE BOXES: A core box is a type of a pattern used fore making cores. It is made of wood, brass,
aluminium or any suitable material.

TYPE OF BOXES
1.
2.
3.
4.
5.

Half core box.
Dump core box
Split core box
Right and left core box
Gang core box

CORE MAKING MACHINES: Fore production work machine are used for core making, where
jolting, squeezing or blowing machine rams core sand mixture.
The most commonly core making machine are
1.
2.

Core blowing
Core shooter.

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1. Objective: To prepare a v-block mould by floor moldings process and sand mould casting.
2. Tools & Equipment used:
Pattern, Moulding boxes, Rammer, Well prepared moulding
sand (green sand), Trowel, Wood smother, Strike off bar, Sprue cutter, Draw spike, Lifter,
Slicks, Bellow, Small brush, Mallet, Vent wire, Furnace, Chisel, Hummer, Wire brush, Hacksaw,
grinder, and file.
3. Materials required: Lead (Melting Temperature = 3500C)
4. Drawing: See Diagram
5. Procedure:
a) Select a mounding box suitable for then pattern provided. It should be large enough to allow
some space around the pattern for ramming of sand.
b)

Place the drag part of the moulding box upside down on the floor and place the lower part of
the pattern in the center of the drag. The drag is then filled and rammed properly with well –
prepared green sand. The excess sand is then cut off to bring it in level with the edges of the
drug with the help of a strike of bar. Then drag is turned downside up along with lower half
pattern in it and sprinkle small amount of parting sand over the top surface to avoid sticking.
Now turn the drag up side down with lower half of the pattern in it.

c)

Place the cope over the drag in its proper position in alignment with locking pins. Then
assemble top part of the pattern in it.

d)

Sprinkle parting sand over the surface of the drag and the pattern.

e)

Place the runner and riser in position and fill the cope with green sand and ram it properly.
Cut off excess sand to bring it in level with the edges of the cope.

f)

Remove the runner and riser to from the pour basin.

g)

Using a venting wire perform the venting operation. It is done to allow exit of gases and
steam generated during pouring.

h)

Remove the cope from the drag, and three after remove the pattern from cope and drag.

i)

Repair the mould cavity for any small damage caused while removing the pattern; cavity
should be free from any undesirable sand particles.

j)

The cope and drag are then locked with locking pins. The mould is thus ready for pouring.

k)

Melt the metal, and then pour the molten metal through pouring basin continuously till the
riser is filled and allow it to solidify.

l)

The solidified casting is then removed by breaking the mould and cleaned by removing
adhering sand. The sand is recycled and reused.

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Precautions
a) Ramming of filled sand should be proper and uniform through out surface of drug and cope.

b)

Place the pattern in the drag properly.

c)

Make the gate properly with broadening at the gate point.

d)

The cope and drag should fit properly.

e)

Take out the pattern carefully causing minimum damage.

f)

Molten metal should be poured in to the mould cavity carefully, to avoid any accident.

g)

The riser should be filled completely.

h)

Do not touch casting immediately after from the sand mould.

Mould Assembly

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SMITHY SHOP

SYLLABUS

Introduction to forging tools; equipments and operations; forgability of metals; exercises on simple
smithy; forging exercises

Instructor Incharge: Mr. shukdev singh

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SAFETY PRECAUTIONS
SMITHY SHOP
1. Always wear proper apron & gloves while working in the smithy
shop.
2. remove the wristwatch, ring & bangles if worn, while working.
3. Wear goggles or a face shield during operation.
4. Always use the appropriate tongs whose jaws fit the shape of the
forging to avoid slipping of the work piece.
5. check that the hand hammers & sledge hammers are securely
fastened with a wedge to prevent loosening of hammer while in
use.
6. Do not use hammers with damage handles.
7. Hot stock & anvil should be properly cleaned & free from scale,
film or grease if any.
8. Do not use the mushroom head chisel, hammers & flatters.
9. never
10. touch the hot job with your hands or other parts of the body.
11. Heat the job carefully as per forgeability requirements of to the
metal.
12. Hammering should be done on the
13. red- hot job only

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INTRODUCTION: Various machine part are manufactured by different process such as casting,
machining, forging, etc. forging me be defined as the plastic flow of metal by the application of
compressive forces in which a metal is altered in shape permanently without rupture. The application
of heat increase the plasticity of metal thus making it possible to conduct the operations necessary
for the fabrication of various shapes of product.
This is one of the oldest manufacturing process. The working of the small object heated in
an open hearth furnace, operated by manual labour, is known as ”SMITHING” whereas, the large
objects heated in closed hearth furnaces and working by heavy hammers or forging machines are
called “FORGING”. In smithy and forging shop ones motto should be “THINKING BEFORE, ACT
AFTERWARDES”.
Forging processes are extremely important in any machine building industry such as in the
manufacturing of tractors, Automobiles, Agriculture machinery, Ship building, and Locomotive
building Rail Road equipments, Aeroplane manufacturing and cutting tools etc.
It has the following advantages of the forging processes
1) It refines the structure of metal.
2) It increases the strength of metal.
3) It saves time, material & labour.
FORGE ABILITY OF A METAL:
Forge ability is the capacity of a heated metal to undergo deformation under compression with out
rupture.
FORGING TEMPERATURE:
Forging is a hot working process. In this heating on a material to proper temperature is essential as
excessive temperature may result in burning of the material that destroys cohesion between the
atoms. Insufficient temperature also result in cold working defects like strain hardening and
cracking. To obtain a fine grained structure the forging operation must be finished at lower
temperature. So that no grain growth takes places.
FORGING TEMPERATURE FOR VARIOUS METAL
Sr. no
1.
2.
3.
4.
5.
6.

Name of metal/alloy Forging temp. c
starting
Mild steel
1300
Wrought iron
1250
Medium carbon
1250
steel
High carbon steel
1150
Stainless steel
1180
High speed steel
1250

Finishing
750
900
750
825
940
970

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7.
8.
9.
10

Carbon tool steel
Spring steel
Copper brass &
bronze
Aluminium &
magnesium alloys

900
1000
950

800
900
600

500

/

350

EQUIPMENTS USED:
1. Open hearth furnaces.
2. Blower
3. Anvil
4. Swage block
5. Pressure or mechanical hammer
TOOL USED IN A SMITHY SHOP:
1. Supported tools: Anvil, swage block, iron blocks.
2. holding tools: various type of tong.
3. striking tools: hammers
4. cutting tools: chisels
5. forming & finishing tool: flatter, set hammer, hand hammer, fullers, swages, punches.
s. no
Tool
Part name
Material
1.
Anvil
Face body stand
Cast steel
2.
Hammer
Body
Medium carbon
steel
3.
Tong
Mild steel
4.
Hot chisel
High carbon steel
5.
Cold chisel
Medium carbon
steel
6.
Flatter
High carbon steel
7.
Punch
High cabon steel
8.
Drift
High speed
steel
9.
Fuller
High carbon steel
10.
Swages
High carbon steel
11.
Swage block
Cast iron, cast steel
1. OPEN HEARTH FURNACES: It is used for heating the metal for hand forging.
The main part of a forging furnace are shown as under.
Hearth: the iron bottom where wire fire is lightened is known as hearth.
Hood: the upper part of the furnace is called hood.
Chimney: chimney is fitted on the upper end of the hood. It is used for the purpose of easy
escaping of exhaust gasses and smoke.
Water tank: a small iron tank is attached with the hearth of the furnace.

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ACCESSORIES:
I.
Blower
II.
Regulator
III.
Showel
IV.
Poker
V.
Raker
TOOLS USED:
1. FURNACE: the space inside the hearth is filled with soft wood. It is slowly brought to the
center of the hearth regulating the air supply from the blower.
2. ANVIL: It is used to support the work while hammering or carrying out other forging
operations. It is made up of a malleable cast iron, steel or wrought iron.
i.
ii.
iii.
iv.
v.
vi.
vii.
viii.
ix.

Body
Horn or beak.
Chipping block.
Face.
Hardie/ square hole.
Round hole.
Tail.
Legs.
Stand.

The central part is known as body. Horn or beak is used while bending or ringing making. Face is
important part of the work is done on face. Tail is used for right angle bending purpose.
3. HAMMERS: Hammers are used as striking tools. These are used for finishing flat or curved
surfaces.
These are classified as under:
i.
Hand hammer: ball peen, cross peen, straight peen hammer weight ¼ kg to 2kg.
ii.
Sledgehammer: double face hammer weight 4kg to 10kg.
iii.
Power hammer: spring hammer, pneumatic hammer, and steam hammer, drop hammer.
4. TONG: Tong are used for holding and turning hot metal pieces. Depending upon their uses
& according to work size & shapes. A tong has two legs riveted from a suitable place. These
are made up of mild steel. Various type of tong used in forging shop.
i.
ii.
iii.
iv.
v.

Round hollow bit tong: used to grip round bars only.
Square hollow bit tong: used to grip square bars only.
Close flat tong: used to grip flat only.
Pick- up tong: used to pick the hot job in the furnaces.
Chisel tong: used to holding the chisel for cutting purpose.

6. CHISEL: Chisel are used for cutting metal pieces hot and cold stat. chisel are dividing into
following categories:
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i.
ii.
iii.

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Cold or flat chisel: it is made up of carbon tool steel. It is use for cutting metal in cold
stat.
Hot chisel: it is made up of tough tool steel generally high carbon steel.it is use for
cutting metal in hot state these are not heat treated.
Hardie set: these chisel are normally made in pair consists of a top tool, which is a chisel
and the bottom tool, which is called hardie.

FORGING OPERATIONS: In forging shop, the following operation are used to change the shape
and size of the raw material to the finished form. The typical forging operation are:
i.
ii.

iii.
iv.
v.
vi.
vii.

Drawing down: drawing down is the process of increasing the length of any work pieces,
while the cross-section area is reduced.
Jumping & up setting: it is the operation in which the thickness of the bar or crosssection is increased at increasing at the expense of its length. If the and of the bar is
required to be upset, its end is heated to a bright red height and hammered while holding
the bar vertically on an anvil.
Swaging: swaging is the process used to form or finish different shapes such as circular,
hexagonal and square etc.
Flattening: flattening process is done on an anvil face. Hot work piece is placed on anvil
and flatten the work piece with the help of flatter and hammers blow.
Punching & drifting: in thicker work piece the holes are punched. The work piece is
heated to 1000c and placed on the anvil hardie hole as explained above.
Bending: the process of giving desired angels or curvature to hot piece is known as
bending. The process is done on the edge of anvil or on chipping block.
Forge welding: the process of joining two metal pieces by heating & hammering is kwon
as forge welding. The metal piece to be welded are cleaned & heated in a furnace up to
the welding temp.

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JOB NO. 1
Objective:

Making of Pipe Clamp

Tools and Equipment: Open Hearth Furnace, Anvil, Hammers, Chisel, Tongs, Flatter, Swages,
Fullers, Hacksaw, Bending link etc.
Measuring Instruments: Brass Rule, Template, Try square etc.
Materials: Mild Steel Flat 30 mm+ 120mm long.
Procedure:
1.
Check the tools and equipments required and see that they are in good working.
2.
Do marking on the raw material by scale and cut the pieces as per dimension.
3.
Start the forge and heat the job up to the forge temperature which depends on the
materials (for steel 1080 to 12500 C) or till the materials is red hot. (See figure A).
4.
After the job is red hot, bring out form the forge and set on anvil with the help of close
flat tongs and forge with hammer as shown in the figure (B).
5.
Again make the job red hot and set down the other end about 20mm long Continue till
the end elongates to about 40mm length. Make a uniform taper as round shown in the
figure. (C).
6.
Heat the job again and as shown in the figure. (D).
7.
Heat the while job again and cut the excess metal to maintain dimensions. Then do
finishing operation. See figure (D).
Precautions:
1.
Don’t were wristwatches and finger ring while working.
2.
Don’t use mushroom-heated tools.
3.
Always use suitable tongs and tools.
4.
Equipment and tools should be cleaned of any oily substance.
5.
Start hammering only on the red-hot job only.
6.
Do not wear silky clothes, as they are prone to catch fire.
7.
Do not touch the job with bare hands.
8.
Make sure that the job is not affecting your body.

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PIPE CLAMP

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JOB NO. 2
1.

Objectives: Making a flat chisel

2.

Tools used: Furnace, anvil, hammer, tongs, flatter, chisel grinder, steel rule, try square

3.

Materials used: Mild steel round bar φ 20mmX150mm

4.

Drawing: See Diagram

5.

Procedure:
a) Do marking on the raw material by scale and cut the piece as per the dimension with the help
of hexa frame. (See diagram)

b) Start the furnace and heat the job upto forgeable temperature (1250° C) or till metal is red hot
c) Keep the red hot metal piece on the anvil with the help of tongs. Then give octagonal shape to the
job with flatter and hammer. (See diagram)
d) Re heat the octagonal job and place horizontally on the anvil with tongs and taper one end. To
make chisel head with hammer. The other end of the job is taper flattening to make chisel
mouth with flatter and hammer. ( See diagram)
e) Heating the whole chisel again, cut the access metal to maintain dimensions then do finishing
with the chisel.( See diagram)
f) Keep the chisel in a restricted place for cooling in air.
g) After the job has cooled grind the cutting edge of the chisel to 60 ° angle. (See diagram)
h) Do hardening and tempering on the cutting edge of the chisel
6.

Precautions

a) Don’t wear wrist watched and finger rings while working
b) don’t use mushroom headed tools
c) always use suitable togs as per the job shape and size
d) Clean the oil substance from the tools
e) Heat the job carefully as per the forgebility of the metal
f) Start hammering on the red hot job only
g) Take great care during hammering of the job. Improper hammering may cause job to jump out of
the tongs and hit somebody
h) Do not touch the hot jobs

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MAKING A FLAT CHISEL

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MACHINE SHOP

SYLLABUS

Machines, grinders etc; cutting tools and operations; exercises involving awareness

Instructor Incharge : Mr. Prem Chand

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SAFETY PRECAUTION
MACHINE SHOP

1. Always wear proper fitting apron/lab coat before starting work
in machine shop. Do not wear loose clothes.
2. Always wear safety goggles to protect your eyes against any
flying chips or dust.
3. Keep your hands away from the moving cutter or work piece.
4. Cover the pulleys & belts with safety guards while working.
5. Never let your clothes & hand come in contact with the
revolving chuck, pulleys, belts, etc.
6. Work piece should be held tightly between the live & dead
centers.
7. Don’t touch the chips while the same are being generated by the
machine because these are extremely hot.
8. Bee sure that cutting tool is tightly held in tool post.
9. Do not touch the tool tip during grinding of the tool.
10. Don’t give excessive feed to the cutting tool. it damages the
tool tip & may even cause accident.
11. you must always know the position of fire extinguisher & first
aid box in the shop.

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MACHINE SHOP
The shop where machining operations are performed. Machining is a manufacturing process in
which the raw material is processes by removing unwanted material with the help of machines.
Different machine used in machine shop are:
1.
2.
3.
4.
5.
6.
7.

Lathe machine
Shaper
Milling machine
Planning machine
Drilling machine
Grinding machine
Threading machine

LATHE
A lathe is a powered mechanical device in which the work is held and rotated against a suitable
cutting tool fore producing cylindrical forms in the metal, wood or any other machinable material.
TYPE OF LATHE
a)
b)
c)
d)
e)
f)
g)
h)

Precision lathe
Tool room lathe
Capstan and turret lathe
Automatic lathe
Speed lathe
Engine lathe
Bench lathe
Special purpose lathe
THE PRINCIPLE OF LATHE

1.

BED: The IT is the base or foundation of lathe. It is casting made in one piece. It holds or
support all other parts of lathe.

2.

HEAD STOCK: It is a permanently fastened on the innerways at the left hand end of the bed.
It supports spindle and driving arrangements. All lathe receive their power through head
stock.

3.

TAILSTOCK: It is the counter part of head stock of is situated at the right end of the bed. It
is used fore supporting the work when turning on centers or when a long component is to be
held in a chuck.

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4.

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CARRIAGE: It is located between headstock. It can slide along bed guide ways and be
locked at any position by tightening the carriage lock screws. It consist of following

Five main parts;
1.

APRRON: It is fastened to saddle. It contains gears and clutches for transmitting motion
from feed rod and hand wheel to the carriage. Also split nut which engages with the lead
screw during threading. The Clutch mechanism is used for transmitting motion from feed rod
whereas the split nut along with the lead screw moves the carriage during thread cutting.

2.

SADDLE: It is made up of H shaped casting. It aids saddle to slide on bed guideways by
operating hand wheels.

3.

COMPOUND REST: It supports the tool post and cutting tool in its various positions. It may
be swiveled on the cross-side to any angle in the horizontal plane.

4.

CROSS-SLIDE: It is provided with a female dovetail on one side and assembled on top of
saddle having a mail dovetail.

5.

TOOL POST: It is used to hold various tool holders and tools. Three types of tool post
commonly used are;
a)
Ring and rocker tool post.
b)
Square head tool post.
c)
Quick change tool post

6.

LEGS: The are supports which carry entire load of the machine. Legs are casted and it is
placed on the floor of the shop on foundation by grouting. The left leg acts as a housing for
the motor, the pulleys and the counter shaft at the same time the right leg acts as a housing or
the coolant tank, pump and the connecting parts.
SPECIFICATION OF LATHE: The size of the lathe is specified by one of the following
ways:
A)
Length of the bed.
B)
Distance between centres
C)
Diameter of the work which can be turned between the ways
D)
Swing over carriage

SHAPER
Shaper is a versatile machine which is primarily intended for producing flat surfaces. The
surfaces may be horizontal, vertical or inclined. This machine involves the used of single
point tool held in a properly designed tool box mounted on a reciprocating ram.
CLASSIFICATION OF SHAPERS;
1.

According to the ram driving mechanism
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a)
b)
c)

/

Crank shaper
Geared shaper
Hydraulic shaper

2.

According to position and travel of ram
a)
Horizontal shaper
b)
vertical shaper

3.

According to direction of cutting stroke
a)
Push cut shaper
b)
draw cut shaper

4.

According to design of table
a)
Plain shaper
b)
Universal shaper

MILLING
It is a machine tool in which metal is removed by means of a Revolving cutter with many teeth, Each
teeth has an edge which removes metal.
TYPE OF MILLING MACHINE
(1)

COLUMN & KNEE TYPE MILLING;
(a)
Horizontal milling machine (b) vertical milling machine
(c)
Universal milling machine.

(2)
(3)
(4)

PLANER MILLING MACHINE
FIXED BED TYPE
SPECIAL purpose milling machine.
PARTS OF MILLING

(1)
(2)
(3)
(4)
(5)
(6)
(7)

BASE; It is a heavy casting on which column and other parts are mounted .
COLUMN; There are guide ways on the front face of the column on which knee slides.
KNEE; It supports the saddle table, work piece and other damping device.
SADDLE; It is mounted on the knee and can be moved by a hand wheel.
TABLE; It is mounted on the saddle and can be moved by hand or automatic power feed.
ARBOR; It holds and drives different types of milling cutters.
SPINDLE; It gets power from gears, belt drivers to drive the moter . It has the power to add
or remove milling cutter on the arbor.

OTHER TOOLS IN MACHINE SHOP
Measuring Tools
1.
Steel Rule
2.
Vernier Caliper (L.C.-0.02mm)
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3.
4.
5.
6.
7.
8.
9.
10.
11.

/

Out Side Micro Meter (0.01mm)
In side caliper / out side caliper
Threading gauge
Vernier height gauge
Dial indicator
Surface gauge
Radius gauge
Feeler gauge
Surface plate

CUTTING TOOLS
1.
Single point cutting tool
2.
Internal / external threading tool
3.
Parting off tool
4.
Boring tool
5.
Knurling tool
6.
Round split die / spring die
7.
Tap set
8.
Twist drill
9.
Taper shank drill
10.
Smooth file
MISCELLANEOUS TOOLS
1.
Double ended spanner
2.
Ring spanner
3.
Allen key set
4.
(l) shape socket wrench
LATHE MACHINE ACCESSORIES & ATTACHMENT
1.
Live Centre / dead center or revolving center.
2.
Job or dog carrier
3.
Mandrel
4.
Collet chuck
5.
Drill chuck
6.
Steady rest
7.
Face plate
8.
Angle plate
9.
Three jaw chuck or four jaw chuck

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Objective: To prepare the job as per the specifications provided
Machine Tools used: Lathe Machine (Specification H.P. =0.75 H.P. over all length 1600-2000 mm,
Swing Dia =455-575 mm.
List of tools: Engg. Steel Rule 6”, Outside caliper, Vernier calipers, Flat smooth file, Single point
cutting tool, Knurling tool, Center drill, Drill chuck ½”, Spanner set, Parting off or necking tool,
Thread gauge, Threading tool, Parting tool, Lathe Dog carrier etc.
Materials Used: Mild steel Bar (40 mm dia.)
List of Operations: Cutting, Facing, center drilling, Plain turning, Taper turning, Necking,
Knurling, Threading, chamfering, Filing Oiling.
Drawing: See diagram
Procedure:
1.
Understand the job drawing thoroughly and plan the job.
2.
Cut off a 130mm long piece from 40 mm dia. Bar.
3.
Hold the work piece in the Lathe chuck and perform facing and center drill operations.
Repeat the same on the other side also.
4.
Hold the job in between live and dead centers.
5.
Perform plain turning (L=35mm, dia, chamfering and knurling operations on one side and
interchange the faces axially.
6.
perform plane turning by swiveling the compound rest at an angle 4
7.
Now start threading by setting levers as per requirement.
8.
After filing if required, take off the job from m/c and do oiling in the whole job for the
protection from the rust.
Precautions:
1.
Don’t wear loose clothes while working on the machine.
2.
Work piece should be held tightly between the live and dead centers.
3.
Always clean machine before use.
4.
Cutting tools should be held tightly in the tool holder.
5.
Never let your clothes and hand come in contact with the revolving chuck, pulleys etc.
6.
Do not touch the chips when machine is removing them
7.
Do not give large feed to the cutting tool.

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Different operations on Lathe Machine

Swiveling angle = Half of the taper angle = 4°
All Dimensions are in mm
Tolerance = ± 0.5mm

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WELDING SHOP

SYLLABUS

Introduction to different welding methods; welding equipment; electrodes; welding joints; welding
defects; exercises involving use of gas/electric arc welding.

Instructor Incharge : HPS Saini

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SAFETY PRECAUTIONS
1.

Protection of eyes and face
Never look at a welding arc without shield as the ultraviolet rays and infra-red rays emitted
from the arc can harm the eyes as well as skin of the face. Always replace the clear cover
glasses when they become spattered.

2.

Protection of rest of the body from radiations and weld
Always wear flexible gauntlet gloves and a leather apron when welding in order to save the
rest of the body from weld metal spatter and sparks, and ultra violet rays and inra red light
emitted by the arc. Shoes worn by the welder should be high topped. Street shoes will not
prevent globules of molten metal from dropping into the shoes.

3.

Use of specified current and electrodes for arc welding
Always use welding current and electrodes for the particular application of metal and its size
as specified by the supplier of the equipment.

4.

Handling the workpieces
Never touch the hot ob with hands. Always use a pair of tongs for this purpose.

5.

Safety during chipping
While chipping the slag off the welded layer remember that it can be very hot and start the
chipping when the pieces are at lower temperature. Chip only with appropriate chipping
hammer and in such a ways that the chips flow away from the persons.

6.

Miscellaneous found of use. Any eye drops containing sulpha acetamide (Locula 20%) can
also be used.

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INTRODUCTION:

VARIOUS TYPES OF WELDING
(a)

Forge Welding: This welding is done by the black-smiths. In this two similar metal pieces
are heated upto the plastic stage in the furnace. Then it is hammered so that a homogeneous
mixture is formed at the joint. The surface to be joined should be cleaned and made free of
any foreign particle, this is done by brushing.

(b)

Gas Welding: Gas welding is the process in which a gas flame is used to raise the
temperature of the metals to be joined. The metals are heated up the melting. The metal flows
and on cooling it solidifies. A filter metal may be added to the flowing molten to fill up
cavity made during the end preparation. Many combinations of gases are used in gas
welding. But the most common of these is oxygen and acetylene.

(c)

Arc Welding: The welding in which the electric arc is produced to give heat for the purpose
of joining two surfaces is called electric arc welding.
Principle: Power supply is given to electrode and the work. A suitable gap is kept between
the work and electrode. A high current is passed through the circuit. An arc is produced
around the area to be welded. The electric energy is converted into heat energy, producing a
temperature of 3000ºC to 4000ºC.

(d)

Resistance Welding: Resistance welding is a group of welding processes wherein
coalescence is produced by the heat obtained from resistance of the work to the flow of
electric current in a circuit of which is the work is a part and by the application of pressure.
No filler metal is needed.

Fundamentals of Electric Resistance Welding
1.

The two factors or variables mainly responsible for resistance welding are

(i)

The generation of Heat at the place where two pieces are to be joined.

(ii)

The application of pressure at the place where a weld joint is to be formed.

(e)

Thermit Welding: It is used on those places where there is no availability of electric supply
or gas. It is a compact unit and can be moved easily upto the site. It consists of a conical
shape vessel with a brick lining inside. Mixture of powdered aluminium and iron oxide is
placed inside the vessel. This mixture is heated by the surface upto molten stage, due to the
reaction the Aluminium is converted in Aluminium oxide.

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WELDING EQUIPMENTS
Various equipments used for Arc welding are as under:
1.

Motor Generator Set: In this a generator is driven by a suitable AC motor. The average
voltage of the generator is 25 volt. The current ranges from 25 to 100 amperes, the voltage in
the generator is variable. The voltage can be set to the desired value with the help of rheostat.

2.

Diesel Engine Generator Set: In this set, the drive is given by a diesel engine. Rest of the
system is same as in case of A.C. motor generator. Diesel engine generator sets are used in
the areas where electricity is not available.

3.

Transformer rectifier set: It allows the current to flow through it only in one direction.
Because it has a one way valve or solid rectifier installed on the electrode side of the
secondary coil. The set can supply straight polarity and reverse polarity power supply. The
rectifiers are of two types:
(i)
(ii)

4.

Silicon diode
Selenium plate

Welding Transformer Set: It is used to step down the voltage supply. It consists of a
primary and secondary circuit. The input is given to primary winding. By electromagnetic
induction the current flows through the secondary coil. The output can be controlled as per
requirement.

WELDING ELECTRODES
Electrodes are of two types:
1

Coated electrodes

2.

Bare electrodes

Coated electrodes are generally applied in arc welding processes. A metallic core is coated with
some suitable material. The material used for core is mild steel, nickel steel, chromium molybdenum
steel etc. One end of the coated core is kept bare for holding.
Bare electrodes produce the welding of poor quality. These are cheaper than coated electrodes.
These are generally used in modern welding process like MIG welding.
Electrode Size
Electrodes are commonly made in lengths 250 mm, 300 mm, 350 mm, 450 mm and the diameters
are 1.6 mm, 2 mm, 2.5 mm, 3.2 mm, 4 mm, 7 mm, 8 mm and 9 mm.
Functions of Coatings
1.

To prevent oxidation.

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2.

Forms slags with metal impurities.

3.

It stabilizes the arc.

4.

Increases deposition of molten metal.

5.

Controls depth of penetration.

6.

Controls the cooling rate.

7.

/

Adds alloy elements to the joint.

Specifications of electrodes:
An electrode is specified by six digits with profile letter M. These six digits indicate the following
matter:
M: It indicates that it is suitable for metal are welding.
First Digit: First digit may be from 1 to 8, which indicate the type of coating on the electrode.
Second Digit: It denotes the welding position for which electrode is manufactured. It varies from 1
to 6.
Third Digit: It denotes the current to be used for an electrode. It is taken from 0 to 7.
Fourth Digit: Fourth digit is from 1 to 8. Each digit represents the tensile strength of welded joint.
Fifth Digit: It carries any number from 1 to 5. This digit denotes a specific elogation in percentage
of the metal deposited.
Sixth Digit: It carries any number from 1 to 5 denotes impact strength of the joint.

WELDING JOINTS
1.

Butt Joint: In this type of joint, the edges are welded in the same plane with each other. V or
U shape is given to the edges to make the joints strong.

2.

Lap Joint: This type of joint is used in joining two overlapping plates so that the corner of
each plate is joined with the surface of other plate. Common types of lap joints are single lap,
double lap or offset lap joint.

3.

T-Joint: When two surfaces are to be welded at right angles, the joint is called T-Joint. The
angle between the surfaces is kept 90º.

4.

Corner Joint: In this joint the edges of two sheets are joined and their surfaces are kept at
right angle to each other. Such joints are made in frames, steel boxes etc.

5.

Plug Joint: Plug Joints are used in holes instead of rivets and bolts.

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WELDING DEFECTS
S.No.
1.
2.

Defects
Low penetration of metals into each
other
Cracks in welded metal

3.

Poor appearance

4.

Inclusions

5.

Poor Fusion

6.

Blow Holes

7.

Wraping

8.

Scattering of welding

Reasons
(a) Incorrect current
(b) Fast speed or welding
(a) Wrong selection of electrode
(b) Metal contains too much carbon
(a) Faulty electrodes
(b) Irregular welding
(c) Wrong arc length
(d) Overheating due to high current
(a) Dirty base metals
(b) Higher sulphur content in metals to be welded
(c) Improper removal of slage
(a) Wrong current setting
(b) Wrong clearance between the electrode and work piece
(c) Fast speed of welding
(a) Wrong arc length
(b) Old electrode
(c) Impurities in base metal
(a) Uneven heating
(b) Over heating due to high current
(c) Thin cross-section of metals
(d) Slow speed of welding
(a) High current
(b) Long arc
(c) Faulty electrrodes

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JOB NO. 1
Objective: Beading practice with arc welding
Tools and Equipment: Arc welding machine with all the accessories, try square, hacksaw, steel
rule, hammer, chisel, pair of tongs, chipping hammer, face shield etc.
Material Used: MS-Flat of size 100*64*6 mm – one piece
Electrode: M.S Electrode 3.15 mm dia [SWG 10], length 350 mm.
Procedure:
1.

Marking and cutting the MS Flat

2.

Start the welding transformer machine, and then set the current to approx. 100 amps.

3.

Hold the Electrode at an angle as shown in diagram. Keeping the Flat position & then
complete the welding layer.

4.

Clean with a chipping hammer and a wire brush.

Precaution:
1.

Never look at the welding arc without face shield.

2.

Always wear flexible gloves and leather apron.

3.

Never touch the hot job with hands.

4.

Use specified current and electrodes for arc welding.

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Beading practice with Arc welding

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JOB NO. 2
Objective: To make a butt joint by arc welding.
Tools and Equipment used: Arc welding machine with all the accessories, electrode holder, earth
lamp, try square, hacksaw, steel rule, hammer, chisel, pair of tongs, chipping hammer, face shield
etc.
Material Used: MS Flat of size 100*64*6 mm – two pieces
Electrode: MS Electrode 3.15 mm dia [SWG 10] length 350 mm
Procedure:
1.

Marking and cutting the MS Flat

2.

Start the welding transformer machine, and then set the current to approx. 100 amps.

3.

Tack both the sides of joints. Keeping the flat position of the job, complete the layer.

4.

Clean with a chipping hammer and a wire brush and then check the welding layer.

Precaution:
1.

Never look at the welding arc without face shield.

2.

Always wear flexible gloves and leather apparels.

3.

Never touch the hot job with hands.

4.

Use specified current and electrodes for arc welding.

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To make butt joint by Arc welding

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ELECTRICAL & ELECTRONICS SHOP

SYLLABUS

Introduction to electrical wiring; preparation of PCBs involving soldering applied to electrical and
electronic applications; exercises preparation of PCBs involving soldering applied to electrical and
electronic applications.

Instructor Incharge : Mr. Sumit Bhatia

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SAFETY PRECAUTIONS
1.

Always wear a rubber sole closed shoe, while performing experiments.

2.

Wooden board should be kept under the feet while working on live supply.

3.

Connect the circuit as given in the circuit diagram.

4.

Don’t switch on the supply without getting the circuit checked in series.

5.

Don’t touch the bare joints or terminals.

6.

Follow the procedure given it the manual strictly to avoid any mishappening.

7.

Never touch any bare conductor.

8.

During repairing electrical appliances should be disconnected fro power supply.

9.

Never disconnect a plug point by pulling the flexible wires.

10.

In case of electric fire, power supply main switch be disconnected immediately.

11.

Never use water to extinguish fire. Use sand or CTC fire extinguisher.

12.

Proper earth must be provided.

13.

Before replacing burnt fuse, main switch should be put off.

14.

Never give supply to any point unless you known that no body is working on line.

15.

Safety belt should be used while working on poles.
16.
Electrical appliances should be insulated properly.

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ELECTRICAL & ELECTRONICS SHOP
INTRODUCTION:
ELECTRICAL: Electrical is an essential need of our daily life. It is widely used for domestic as
well as industrial purposes. So it is necessary for the engineering students work. In electrical shop
knowledge is given about the electricity filed of its application, electrical instruments, domestic &
industrial wiring, electrical goods used, symbol & precaution to be kept in mind.
ELECTRONICS’’ electronics is the filed of manipulating electrical current & voltage using passive
& active components that are connected together to create circuits. Electronics circuit rang from a
simple load resistor that converts a current to a voltage to computer central-processing units (CPU)
that contain more than a million transistors. The following indices & documents provides a basic
reference for understanding electric components, circuit & application.
TOOLS:
1. TEST PEN OR LINE TESTER: Test pen has the following function:ii)
To check the supply.
iii)
Loosing or tightning small screue.
It is a very common tool used in electrical shop. A small bulb is fitted inside a transparent
handle. When cheeking the supply the blade is touched to the point & the finger tip is placed on the
backside of the handle. If the bulb glues, it shows that electrical current is flowing through the wire.
2.

COMBINATION PLIER: It is made of steel. It is the combination of cutter & holder. It is
used fir holding, twisting & cutting of wire.

3.

SCREW DRIVER: Screw driver consist of the following parts:- (1) handle (2) blade.
Handle is made up of plastic or wood blade is made of steel. The top of the blade is flattened
screw driver is used to loosen or tighten the screw.

4.

POCKER: Pocker is a sharp edge, tool used to make holes in wood. Holes are made for
nails or screws.

5.

WIRE CUTTER OR NIPPER: It is made of steel and has cutter. It is used for cutting of
wires.

6.

LONG NOSE PLIER: Nose plier is made of steel. They have a cutter for cutting thin wires.
It is used for holding, twisting and cutting wire. Preparing looks and jointing of wires.

7.

BALL PEEN HAMMER: It is made of mild steel having ball on top and face at bottom,
provided with wooden handle. It is used to break the brick, riveting, grooving purpose and
fixing the nails.

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8.

CROSS PEEN HAMMER: It is made of mild steel having cross shape on top and face at
bottom with wooden handle. It is used for fixing clip and nails and making gitties hole in
wall.

9.

HACKSAW: It is made of frame, blade and handle. The blade is fixed in the frame. It is
used for cutting conduit pipe, G.I. pipes and other small metallic materials.

10.

STANDARD WIRE GAUGE: It is a thin circular steel plate having number of slots on its
circumference. It is used to find the gauge of wire.

11.

HAND DRILL MACHINE: It is made of wooden handle. It has gear, chuck and jaw. It is
made of cast iron and steel. It is used for making holes in wooden and metallic objects with
twist drill bit.

12.

ELECTRIC SOLDERING IRON: It consist of a oval copper bit fixed to an iron rod. It is
heated by an electric element. It is used for soldering wires to small joints and commutator
segments.

13.

WIRE STRIPPER: It is used for remove the insulation from wire.

INTRODUCTION TO ELECTRICAL WIRING
TYPES OF WIRING
1.

Cleat Wiring: Cleat wiring is used for temporary purposes. Wooden or porcelain are used at
small distances. PVC or VIR wires are used for this type of wiring.
This system is suitable for temporary installation such as marriage and other functions.

2.

TRS or CTS or Batten Wiring: In batten wiring, the wires are covered with tough rubber
and are fixed on wooden batten. Joint clips are used to hold wires. Wooden batten is used on
gutties inserted in the walls.

3.

Casing and Capping Wiring: In old days it was the most used type of wiring. Wire are
placed in the grooves provided on the casing. It is covered with a strip known as capping,
caring is fixed on the walls with the help of gutties and scress.

4.

Conduit Wiring: In this system, wires are enclosed in conduit pipe to give the wires
mechanical protection. Fire risks are also avoided in this system of wiring. This system is
applied in two ways:
(i)
Surface conduit wiring: In this system the pipes are fixed over the surface of walls
and are visible. Surface conduit wiring is easy to install but is less safe to mechanical
injuries as compared to concealed conduit wiring.
(ii)
Consealed Conduit/Underground Wiring: In consealed conduit wiring the conduit
pipes are buried inside the walls. Grooves are made as per the circuit of the wiring on
the wall with the help of chisel. Pipes, bends and junction box are placed in the
grooves and then covered with cement.
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Job—1
OBJECTIVE: To connect one lamp & control by one way switch.
TOOL USED: Knife, combination plier, screw driver, poker, line tester, wire stripper, hacksaw
& ball /cross pean hammer.

MATERIAL USED:
SR. NO
1
2
3
4
5
6
7
8
9
10

MATERIAL
PVC copper wire 1mm square
Casing & capping 1”
Wooden board 4”x 4”
Bakelite sheet 4”x 4”
One way switch
Batten holder
Wooden round block
Batten nail
Bulb 60 watt
Screws

QUANTITY
1.5mt
1.5ft
01 No
01 No
01 No
01 No
01 No
As per requirement
01No
As per requirement

CIRCUIT DIAGRAM:
PRECATIONS
1. Connection must be tight & right as per circuit dig.
2. Live conductor should be go through switch.
3. After removed the insulation from wires, wire conductors should be twisted with the help of
pliers.

4. Always check in series, do not connect with the direct supply.
5. For safety, should be used MCB/ fuse in the circuit as per rating.
6. Tools should be insulated.
7. Earth must be provided.
PROCEDURE
1. Take the casing (as per requirement), wooden box, round block & fixed on the wiring board with
the help of batten nails & screws with the help of screw driver & hammer as per dimension.
2. Now as per circuit dig. Wires installed. Firstly neutral wire connect with the batten
holder(no. one terminal). Secondly phase wire connected through one way switch with batten
holder ( no. two terminal).
3. Bakelite sheet with switch & batten holder fixed on wooden box & round block with screw &
than capping fitted on casing. Lamp is fixed with batten holder.
Resultant:- job is checked in series, dim lamp has glow & then checked with the direct supply,lamp
glows in full condition.
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ONE LAMP CONTROL BY ONE SWITCH

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JOB NO –2
OBJECTIVE: To connect two lamps in series &control by one way switch.
TOOL USED: Knife, combination plier, screw driver, poker, line tester, wire stripper, hacksaw
& ball /cross pean hammer.

MATERIAL USED:
SR. NO
MATERIAL
1
PVC copper wire 1mm square
2
Casing & capping 1”
3
Wooden board 4”x 4”
4
Bakelite sheet 4”x 4”
5
One way switch
6
Batten holder
7
Wooden round block
8
Batten nail
9
Bulb 60 watt
10
Screws
CIRCUIT DIAGRAM: See diagram

QUANTITY
2.5mt
2.5ft
01 No
01 No
01 No
02 No
02 No
As per requirement
02No
As per requirement

PRECAUTION:
1. Connection must be tight & right as per circuit dig.
2. Live conductor should be go through switch.
3. After removed the insulation from wires, wire conductors should be twisted with the help of
plier.
4. Always check in series, do not connect with the direct supply.
5. For safety, should be used MCB/ fuse in the circuit as per rating.
6. Tools should be insulated.
7. Earth must be provided.

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PROCEDURE:1.

2.
3.
4.
5.

Take the casing (as per requirement), wooden blocks, wooden round blocks, fixed on the
wiring board with batten nails and wooden screws with the help of screw driver and hammer
as per dimension.
Now as per circuit diagram wires installed. Firstly, no. 2 terminal of batten holder (lamp -1 )
& no.1 terminal of batten holder (lamp-2) connected to each other with help of wires.
Neutral wire connected with the no -1 terminal of lamp-1
Phase wire connected through one way switch with batten holder (second terminal ) of
lamp .-2
Batten holders & bakelite fixed one round block & wooden block with screws. Capping is
fitted on casing two lamps fixed on battle holders.

Resultant:- job checed in serious lamps glows dim & then checed with the direct supply, both lamps
has glows dim, because both lamp are connected in series.

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TWO LAMPS IN SERIES AND CONTROL BY ONE
SWITCH

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STAIR CASE WIRING

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JOB NO. 3
Objective: To study the use of soldering iron.
Material Required: Soldering Iron (25W), Solder wire, Flux
Theory: Soldering iron is of pencil type (with 25W electric heater) and needle tip is employed for
PCB with IC component pads closely spaced. For PCB the soldering iron used has wattage between
25W to 40W and temperature varies between 300 to 400 C.

Procedure:
1. Clean the surface of the two components to be soldered either by mechanical means
or by chemical means i.e. by applying flux.
2. Heating the two surfaces by the soldering iron equally to the same temperature at
which when solder is applied to the joint it melts to flow and wet the joint at the
surface.
3. Maintain a little pressure to make a good contact at the interface of the joint till the
melted solder solidifies.
Precautions:
1. Surface of the components should be clean.
2. Do not touch the tip of soldering iron when it is heated up.
3. Check the conductivity of joint.

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JOB NO. 4
Objective: To prepare (different design circuit) PCBs on copper clad plate.
Tools Used: Hand drill, hacksaw
Material Used: Copper clad plate, FeCl3, HCL, H2O, Permanent Marker, Tracing Paper, Paint,
Brush, Tray, Glass rod, Gloves.

Precautions:
1. Gloves should be worn on hands.
2. Don’t directly expose your hands with the mix solution.

Procedure:
1. Make the circuit which you want to make for PCB.
2. Prepare the art work, firstly on plain paper and secondly this art on tracing paper.
3. Transfer the art work into the copper clad plate.
4. Art work placed on the copper clad plate on copper side with the help of permanent marker
and paint.
5. Prepare solution for PCB etching in the tray.
6. Mix solution is made of FeCl3 + HCL + H2O.
7. Place the copper clad plate sheet in mix solution in the tray.
8. Keep the solution for etching for one-two hours.
9. In between that shake the mix solution with the help of glass rod.
10. Pick out the PCB from solution.
11. Clean it and dry it.
12. Tracks are formed according to the art work designed by you.
13. Make the appropriate drills in the PCB where required for insertion of electronic component.
14. Now PCB is ready.

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JOB NO. 5
Objective: To insert the electronic component with soldering iron on PCB.
Tools Used: Soldering iron, wire stripper, hand drill, long more plier, flat file.
Materials Used: Solder wire, soldering flux, emery paper, electronic component – diode,
capacitor-resistor etc.

Precautions:
1. Soldering iron should be earthed.
2. Gloves should be worn on hands.
3. Don’t directly expose your hands with the mix solution.

Procedure:
1. Pick the PCB on which component have to be mounted.
2. Clean the PCB with cleaner.
3. Insert the component one by one on plain component side.
4. Now pick up some flux with the alinger on the copper side on component terminals.
5. With the help of soldering iron pick some solder from solder wire.
6. Now place the picked solder at the component terminal.
7. When all component are soldered, cut the extra terminal of the components.
8. Again clean the PCB.
9. PCB is ready for use.

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SHEET METAL SHOP

SYLLABUS
Shop development of surfaces of various objects; sheet metal forming and joining operations, joints,
soldering and brazing; exercises involving use of sheet metal forming operations for small joints.

Instructor Incharge : Mr. Jaspal Singh

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SAFETY PRECAUTIONS
Sheet Metal Shop
1. Never operate any machine unless you know how to operate
it.
2. Always wear uniform in the workshop, never wear loose
clothes.
3. Never touch moving parts, belts or rotating tools etc.
4. In case of any fire, the electric supply should be disconnected.
5. Do not use blunt cutting edges tools.
6. Appropriate cutting tools and machines must be used for
cutting tin sheets.
7. Do not cut metal heavier than the capacity of snips or shears.
8. Extra allowance must be provided in the sheets while cutting,
so that the finished product is of correct size and finish.
9. Do not place the hot soldering iron on any wooden surface;
keep it on its stand.
10. Avoid breathing of fumes emanating from soldering flux.
11. Save your hands while working on sheet bending or sheet
rolling machines.
12.Be careful while working on sharp edges to avoid injury.
13.While using a chisel for chipping wear goggles.
14.Do not hold small work in your hand while working with
screw drivers or chisels.

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SHEET METAL SHOP
INTRODUCTION
Sheet metal working covers the use off thin metallic sheets with hand tools and sheet metal
machines. Many important engineering articles made up of sheet metal find their application in airconditioning ducts, aircraft industry, agriculture implements, decorative articles and household
goods. For effectively working in sheet metal one should have knowledge of hand tools, sheet metal
machines, properties of metals and thorough knowledge of projective geometry i.e. development of
surfaces.
TYPES OF SHEET METAL
1. Ferrous Sheet
i)
Mild Steel sheets – These are black iron sheets, suspected to rust and corrosion,
mostly used in water tanks and fabrication works.
ii)

Galvanized Iron (GI Sheet) – It is soft steel sheet coated with zinc, which is
corrosion resistance due to zinc coating, used for making air-conditioning ducts,
roofs, boxes, buckets, coolers etc.

iii)

Stainless steel sheets – It is an alloy of high-grade steel with chromium, nickel,
phosphorous and manganese. It is used in household goods, food-processing
plants etc.

iv)

Tin Plate – steel coated with tin is called Tin steel. It is used for making food
containers.
2. Non-ferrous sheets
i)

Aluminum Sheets – It is two and half times lighter than iron but lacks in tensile
strength. Small percentage of other elements like copper, manganese and silicon
is added to make it suitable for production in aircraft industry and other industrial
goods. It is also called aluminum alloy sheets.

ii)

Copper and Brass sheets – These are non-ferrous sheets used in electrical industry
and various other industrial and household articles.

MEASUREMENT OF THICKNESS OF SHEETS
Thickness of sheet is generally measured by gauge number, which is obtained by actually
measuring the sheet thickness with a sheet gauge or wire gauge. Each slot in the standard wire
gauge is numbered, a number, which represents gauge number such as 20 SWG (Standard Wire
Gauge). The more the SWG number, lesser is the thickness of sheet.
TOOLS USED IN SHEET METAL
Marking Tools
1. Steel Rule: Available in different sizes, it could be steel foot rule, folding rule or tape rule.
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2. Steel Square: It is L-shaped piece of hardened steel, used to make square corners, checking
and making right angles.
3. Scriber: It is a steel wire with one end sharp and hardened to mark lines on metallic sheet.
4. Divider: It is used to scribe arcs and circles on metallic sheets.
5. Trammel points: It is used for drawing large circles and arcs
6. Punches:
(a)
Prick Punch: Used for making indentation marks for locating center position for
dividers, it has a taper angle of 30º.
(b)
Centre Punch: Used for marking the location of points and centering hole to be
drilled. it has a taper angle of 90º.
Cutting Tools
1. Straight Snips: It’s blades are straight, it is used to cut 22 SWG or lighter sheets along
straight line.
2. Bent snip: Blades are curved back from the cutting edges; it is used to cut discs and round
articles from sheets.
3. Hollow Punch: Hollow punch is used to cut circular holes on thin sheets.
4. Chisels: This is used for cutting sheets, rivets and bolts.
Striking Tools
1. Hammers: Hammers are used for bending of sheets, smothering of sheets, locking of joints
and riveting work.
(a)
Ball Pean Hammer: General purpose, face is slightly curved, and head is round.
(b)
Square face hammer: It has square flat face, used for flattening of seams
(c)
Raising Hammer: It is used to form flat surface of sheet into curved surface.
(d)
Riveting Hammer: Face is square slightly curved with beveled edges.
(e)
Mallet: Made of good quality of wood or plastic used whenever light force is
required.
Supporting Tools
1. Stakes – Stakes are used to support sheets in bending, seaming, forming, riveting, punching
etc. Some commonly used stakes are:
(a)
Hand stake: It is handy with flat face, two straight edges one concave edge, other
convex edge, used for pressing the inner sides of straight joint.
(b)
Half Round stake: It is used for pressing round seam joint on inner side.
(c)
Taper stake: It is used for rounding of tapering jobs such as conical jobs.
(d)
Grooving stake: It is made up of forged steel, used for grooves of different sizes.
(e)
Horse stake: There are two square holes for holding two stakes at a time for carrying
out different operations.

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SHEET METAL WORKING MACHINES
1.

Rolling & Bending Machine: This machine is used to form cylindrically shaped articles;
this machine consists of three rollers that can be adjusted for different radii.

2.

Sheet Bending Machine: This is used for bending and folding the edges of sheet metal.

3.

Swaging Machine: It is used to provide different types of swages to give strength to thin
sheets.

4.

Lever shearing machine: It is used for sheet cutting, round bar shearing mostly used in
sheet metal shop.

5.

Universal Cutting machine: It is used for cutting sheet into desired shape & size machine
has two circular tools used for circle cutting.

6.

Grooving machine: It is used to make grooves; depth of groove can be adjusted.

SHEET METAL JOINTS
1. Lap Joint – It can be prepared by means of soldering or riveting.
2. Seam Joint – When two or more sheets are folded and fastened together is called seam joint.
There are two types of seam joints.
i)
Single Seam Joint
ii)
Double Seam Joint
3. Groove Seam Joint – In this joint two single edges are hooked together and flattened with a
small mallet to make them tight, seam is then grooved with a hammer and a hand groover.
4. Wired Edge – It is one of the methods of strengthening the thin metal by turning over the
edge on a wire in it.
5. Hinged Joint – It is used for easy movement of opening or closing doors, window etc.
6. Cap Joint – It provides another useful form of locked seam joint.
7. Hem Joint- This is turning over the edge of the sheet to give the strengthening on the edge of
the sheet.
SHEET METAL OPERATIONS
1. Measuring and Marking – Sizes are marked on large sheet to cut the latter into small
pieces.
2. Development of Surface (Laying Out) – Operation of scribing the development of surface
of the component on the sheet together with the added allowance for overlapping, bending,
hammering etc.
3. Cutting and shearing – The term shearing stands for cutting of sheet metal by two parallel
cutting edges moving in opposite direction.
4. Hand Forming – It stands for shaping, bending of sheet metal in three dimensions in order
to give the desired shape and size of final product.
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5. Nibbling – It is a process of continuous cutting along a contour which may be of straight or
irregular profile.
6. Piercing and Blanking – Piercing is basically a hole punching operation while blanking is
an operation of cutting out a blank.
7. Edge Forming or Wiring – Edges of sheet metal products are folded to provide stiffness to
the products and to ensure safety of hand due to sharp edges.
8. Joint Making – Sheet metal parts can be joined by folded joints, riveting, welding, brazing,
soldering, self-tapping screws, screwed fastening, and by adhesives.
9. Bending – Bend in sheet metal is to be bent at different angles to shape it to required form.
10. Circle Cutting – It is an operation of cutting circular blanks or curved contours with the help
of circular cutting machines.
11. Hollowing – It is the process whereby a flat sheet metal is beaten up into spherical shape by
placing the metal upon a sand bag or hollowing block, beating with hollowing hammer,
starting from boundaries towards center.
12. Raising – It is the process of hammering the metal from oxide to form a hollow article,
working around from center towards edge.
13. Turned over Edge – It is the method of strengthening the thin metal at edge. The edges are
turned with some radius.
14. Swaging – This is also a method of strengthening thin sheet metal by making impressions in
the bodies. It is done by machine or by hand.
SAFETY WHILE WORKING IN SHEET METAL SHOP
1.
2.
3.
4.

Since in sheet metal work we used sharp tools to cut sharp cutting edges. Be careful on
working on sharp edges to avoid injury.
Avoid using any tools whose edges are blunt or out of order.
Appropriate cutting tools and machine must be used for cutting tin sheets.
Extra allowance must be provided in the sheets while cutting so that furnished product is of
correct size and finish.

SOLDERING
Soldering is a process of joining two metals by using low temperature below 400° C by metal alloy
called solder (alloy of lead + tin)
Process – Surface to be joined are cleaned and placed on each other, flux is applied to prevent
oxidation. Zinc chloride is commonly used as a flux. Soldering iron is heated either electrically or by
some external heat. Then hot end is dipped into the flux and solder is pressed against the surface to
be joined. Melting the solder forms the joint.
Applications: Soldering is widely used in radio and television work for joining wires etc.

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Advantages: Cost is low, equipment is very simple and cheap, provides positive electrical
connection and properties of base metal are not affected.
Disadvantages: Joints formed are weak.
BRAZING
The process of joining two metal surfaces by heating and adding a non-ferrous alloy Brazing Spelter
(Copper + Zinc) with melting point above 400° C is known as Brazing.
Process: Surface to be joined are cleaned and placed in joining position. Flux Borax is sprinkled
between the joining pieces. The heat is given to the surface and the filler metal. The molten filler
metal flows to the surface to be joined.

Brazing Methods:
1.
Gas Torched Brazing: In this process oxygen – acetylene torch is used.
2.
Furnace Brazing: The surfaces to be joined are placed in a furnace already hot.
3.
Dip Brazing: The surfaces to be joined are dipped in mortar filler metal.
4.
Electrical Brazing: In electrical brazing heat is produced by resistance or induction method.
Applications: Brazing is used for electrical items, radiators, heat exchangers, pipes fitting, and tool
tips.
Advantages: It is useful for joining dissimilar metals, less skilled is required, cost of operation is
less, good finish is obtained, and thin section can be easily joined.
Disadvantages: Low strength, not applicable for hardened steel and aluminum alloys.

Development of surfaces of various objects
A layout of the complete surface of a three dimensional object on a plane is called the
development of pattern. Development is the term frequently used in sheet metal work where it means
the unfolding or unrolling of a detail into a flat sheet called pattern.
Practically, the development consists of drawing the successive surfaces of the object in its true
shape and size with common edges joined together.
Methods of pattern development
There are three methods in general use by means of which surface of solids may be geometrically
developed.
(i)

Radial Line Method: - a radial line method id used for those objects such as cones and
pyramids, the sides of which converge to an apex.

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(ii)

Parallel Line Method: - This method can be applied to the development of pattern for
elbows, T-pipes intersection of pipes of equal diameter, cylindrical articles.

(iii)

Triangulation Method: - This method is universally applied to solve a large number of
developments, problems. This system consists in drawing an elevation and plan of the object
to be developed, dividing the surface of the plan into a suitable number of triangles, finding
the true lengths of the triangle sides and building a pattern triangles in there correct relation
to the triangles already shown in the plan.

Theory for Development Surface of a Cone by Radial Line Method
Procedure:Draw the elevation OQR and plan of the cone. With OR equal to slant height as a radius
describe a long arc QQ.
Divide the plan of the cone into any number of equal parts (e.g.12) By points 1, 2, 3…12.
From Q mark of along arc QQ 12 equal parts, each equal to one of the division of the arc. Join the
12th point to the center point O. OQQ will be the required development of the cone.

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JOB NO. 1
Objective: - To make a funnel using G.I Sheet as per dimensions provided.
Tools & Equipment used: - Steel Rule, compass, pencil, Eraser Straight snip, Bent snip, mallet,
Hammer files, Stakes, spring divider, Bench vice, Pliers, scriber soldering iron, Solder, flux.
Materials used: - Galvanized iron sheet 28 SWG.
Procedure: Ex I: - Body of Funnel
1.

Draw the pattern of body of funnel on a drawing sheet as per dimension by Radial line
method as shown in diagram

2.

Mark the allowance for flange and lock seam joint.

3.

Cut the pattern from drawing sheet with sharp blade

4.

Keep the cut out pattern on G.I sheet and mark all around with scriber without moving the
pattern.

5.

Cut the sheet on the marked line with a suitable snip,

6.

Remove the burrs with a smooth file.

7.

Make closed folds on both ends for lock seam joint

8.

Fold the sheet to the shape of body of funnel on funnel stake and lock the seam joint

9.

Flange out top edge of body of funnel as per diagram.

Development of round funnel (Frustrum of a Cone)
Procedure: A round equally tapering body having top and base parallel is Frustrum of a right cone.
Draw the elevation and plan of Frustrum of the cone as shown in figure. Produce the edge line AC &
BD to an apex marked O. Divide the outer circle of the plan in equal number of parts (i.e. 12).
For the development mark a point O in a suitable position and with radius OA from the elevation
describe arc of indefinite length. Take one of the spacing of the outer circle of the plan and divide
the arc into twelve equal parts. Draw another arc of O as centre taking radius equal to OD. Join OB
and OA. ABCD is the required development of frustrum of a cone.

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Ex II: - Bottom piece of Funnel
1.

Draw the pattern for bottom of funnel by triangulation method on drawing sheet as shown in
diagram.

2.

Mark the allowance for soft soldering Lap joint.

3.

Cut the pattern from drawing sheet.

4.

Keep the cut out pattern on G.I sheet and mark all around with a scriber without moving the
pattern.

5.

Cut the sheet on the marked line with suitable snip

6.

Remove burrs with a smooth file.

7.

Form the sheet to required shape.

8.

Soft solder the over lap joint.

9.

Join the bottom piece to the body of funnel by soft soldering.

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Development of a long equal taper Article (bottom of Funnel)
Procedure: Draw the elevation ABCD and plan of the round equal tapering body. Divide the outer
Circle in the plan to number of equal Parts 0,1,2,3 … and a, b, c, d ….. Find the true length BL
taking a1 (aL) as base and vertical height aB at right angles.

To set out the development draw any line OA equal to slant height BD. A as a centre taking radius
equal to any one of the division of the outer Circle, draw an arc on either side of A. Now O as a
centre and take radius equal to any one of the divisions of small circle, draw arcs on either side of O.
now A as a centre, taking radius equal to true height BL, cut previous arcs either sides of O. Now, O
as a centre taking the same true height radius cut previous arcs in either side of A. Now again from
the new formed points (1, 1 b, b) again form the points (2, 2 c, c) by repeating the same method.
Continue this up to six parts on either side of the central line OA. Join the last points g6 on both
sides. ABCD is the required pattern of round taper article. Take allowance on either side for lock
seam joint

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DEVELOPMENT OF LONG EQUAL TAPER ARTICAL

Precautions: 1.

Be careful while working on sharp edges of sheets to avoid injury.

2.

Do not use blunt cutting edges tools.

3.

Appropriate cutting tools and machines must be used for cutting tin sheets

4.

Extra allowance must be provided in the sheets while cutting so that finished product is of correct
size and finish.
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TO MAKE A FUNNEL

All dimensions are in mm
Material : G.I. Sheet 28 SWG

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JOB NO. 2
Objective: - To make a Square box using G.I Sheet as per the dimension
Tools and Equipment used: - Straight snip, steel rule, scriber, Mallet, Hammer, Stakes, pliers,
soldering iron, solder, flux, bench vice, file, spring divider.
Procedure:
1.

Draw a lay out as shown in development on drawing sheet.

2.

Cut the pattern to shape along the line using a suitable snip.

3.

Mark on the G.I Sheet as per the pattern and cut to required shape.

4.

Make the hem edge using mallet and stake.

5.

Make closed folds on both ends for lock seam joint

6.

Make square folds on lines marked A, B, C, D, E, & F

7.

Make lock seam joint after joining both the ends.

8.

Make a bottom piece from G.I Sheet taking required allowance for double lock seam joints as
shown in diagram.

9.

Join the bottom piece with square box by double lock seam joint using stakes and mallet.

10.

Do the soft soldering operation on the corners of double lock seam joints.

11.

File all the sharp corners with file.

Precautions:1.
2.
3.
4.

Be careful while working on sharp edges of sheets to avoid injury.
Do not use blunt cutting edges tool.
Appropriate cutting tools and machines must be used for cutting tin sheets.
Extra allowance must be provided in the sheets while cutting so that finished product is of
correct size & finish.

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Development for square box

Bottom

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To make a square box

All Dimensions are in mm.
Material: G.I Sheet 28 SWG.

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JOB NO. 3
Objective: To make a rectangular tray.
Tools and materials used: Steel rule, Scriber, Divider, Mallet, Stakes, Try square, snip straight (Tin
cutter) Bench shear, file flat smooth, Nylon hammer, Tin sheet piece.
Procedure:
1.

For developing the surfaces (lying out) draw plan, front view and end view of the required
open rectangular box as shown is diagram.

2.

Extend all the lines and cut these lines according to the height of the tray (i.e. 30 mm).

3.

Addition strips of stocks are given along the edges for single hem allowance (6 mm).

4.

All the four corner triangles are cut as shown in diagram for joint making.

5.

Perform the operation of cuttings, shearing edges, hand forming, edge forming, joint making
and bending in to rectangular tray by using above mentioned sheet metal tools by.
I.
Square folding along 12, 23, 34, 41 lines.
II.
Square folding of 15, 26, 37, 48, 2-10, 3-11, 19, 4-12,
III.
Square fold for Hem 56, 78, 10, 11, 9-12.
File the sharp edges with a smooth flat file.

6.

Safety Precautions:
1)

Take precautions while working on sharp edges of sheets to avoid injury.

2)

Appropriate cutting tools and machines must be used fro cutting tin sheets.

3)

Avoid using blunt cutting tools.

4)


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Development of Surfaces (Tray)

Black portion is to be bend (hem).
Hatched portion is to be cut out.

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To make a rectangular tray.

MATERIAL: GI SHEET 28 SWG
ALL DIMENSIONS ARE IN mm.

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JOB NO. 4
Objective:

To make a Book Rake Stand

Tools and Equipment: Steel Rule, Scriber, Divider, Centre Punch, Chisel, hammer, stakes, Try
squre, Leaver, Shearing machine
Material used: Mild Steel sheet 18 SWG 18×14 cms
Drawing : See diagram.
Procedure:
1.
2.
3.
4.
5.
6.
7.
8.

Mark and shear a piece of 18×14 cms M. S sheet with the help of lever shearing machine,
check for Squareness with try square.
Mark two corner edges at diagonals of 20 cm and at base mark a line 50 mm from the edge
with scriber and steel rule
Mark lines on all the three sides of 40 cm distance with scriber and an arc of 30 cm with
divider as shown in diagram
Shear the 20 cm diagonal edges and cut the inner marking piece with the help of chisel
hammer
Clamp the sheet in bench vice and bend the inner cut out portion by hammer at 90º
File the inner cut and portion and the blanking with half round and steel file
Bend the 50 cm mark portion to opposite side at 90º as shown in diagram
Finish the job from sharp edges with a smooth file

Safety Precautions:
1.

Take precautions while working on sharp edges of sheets to avoid injury.

2.

Appropriate cutting tools and machines must be used fro cutting tin sheets.

3.

Avoid using blunt cutting tools.

4.


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DEVELOPMENT OF BOOK RAKE STAND

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BOOK RACK STAND

ALL DIMENSIONS ARE IN MM
MATERIAL: - MS SHEET 18 SWG

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FITTING SHOP

SYLLABUS
Introduction of fitting practice and tools used in fitting shop; exercise involving marking, cutting,
fitting practice (Right Angles), male- Female mating parts practice, trapping practice.

Instructor Incharge : Mr. Jaspal Singh

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SAFETY PRECAUTIONS
Fitting Shop
1. Never operate any machine unless you know how to operate
it.
2. Always wear uniform in the workshop, never wear loose
clothes.
3. Never touch moving parts, belts or rotating tools etc.
4. In case of any fire, the electric supply should be disconnected.
5. Always move the hacksaw in perfect straight and horizontal
direction.
6. Never tilt the hacksaw blade while sawing.
7. The blade should be tightened sufficiently.
8. Grip the job in bench-wise properly,
9. Hacksaw blade should be fixed in proper direction and
tightened
10. Use water as a coolant while sawing.
11. Hold the chisel firmly while chipping.
12. Drill the holes centralizing on pop marks, give gradual feed.
13. Check the dimensions time to time carefully with Vernier
clipper.
14.Tap should be held perpendicular and rotated every half turn
forward reverse quarter turn backward.
15.Use lubricating oil during tapping.
16.Always keep your mind on the job.

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FITTING SHOP
INTRODUCTION
Fitting jobs involves the removal of excess / unwanted material from a blanks with the help of hand
tools so that they could be assembled as specified in drawing. It is done for the assembly practice by
mating surfaces/edges of components leading to assembly.
PHYSICAL PROPERTIES OF METALS
1.

Lustre: Lustre is the ability of a metal surface to reflect light rays.

2.

Colour: Colour is the property of a metal to show specific surface appearance.

3.

Plasticity: This is the property of metal where it can be converted in to required shape and
size by application of heat or pressure both.

4.

Elasticity: It is the property of metal by which it return back to its original shape and size
after removal of external force / pressure.

5.

Malleability: By this property metal can be drawn in the form of a thinner sheet without
failure.

6.

Toughness: Due to this property metal can withstand bending without failure.

7.

Ductility: By this property metal can be drawn in the form of wires without failure.

CLASSIFICATION OF METALS
Metals are classified into two categories:
1. Ferrous Metals – In ferrous metals iron acts as base (highest percentage) metal.. Some other
materials like carbon, sulfur, nickel, etc are also mixed into ferrous metals to change the
properties. They are magnetic in nature. Some ferrous metals are discussed as under.
i)

Steel – Steel is a mixture of iron, carbon and other alloying elements.
(a) Plain Carbon Steel: is a mixture of iron, carbon with negligible alloying elements.
Low Carbon Steel – Carbon content 0.05 to 0.30%.
Medium Carbon Steel - Carbon content 0.30 to 0.60%.
High Carbon Steel - Carbon content 0.60 to 1.50%.
(b) Alloy Steel – Alloy steel is made by combining some percentage of additional
elements like nickel, phosphorous, silicon, chromium, molybdenum in the plain
carbon steel to give strength, hardness, resistance to corrosion properties.
i. Tool Steel – is alloy steel used for making cutting tools, mainly designated
as HSS(High Speed Steel) with 18% tungsten, 4% chromium, 1%
vanadium and 0.7% carbon.
ii. Invar steel – is an alloy steel with 36% Nickel leading to zero coefficient
of thermal expansion used for making precision instruments.

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iii. Spring Steel – alloy steel used for making springs.
ii)

Cast Iron – also referred, as iron is a ferrous metal containing more than 2% of
carbon is known as cast iron. It is hard and brittle material, used in machine beds,
heavy parts of machines.

iii)

Wrought Iron – It is almost pure iron containing 99.9% of iron. It is ductile and soft.

2. Non Ferrous Metals - The metals which has base metal other than iron are known as non
ferrous metals, copper, aluminum, brass, bronze, tin, lead are common non ferrous metals.
i).

Copper: Reddish brown color, soft, ductile, high electrical and thermal conductivity.

ii).

Brass: Alloy of copper and zinc, soft and ductile.

iii).

Bronze: Alloy of tin and copper, wear resistance material.

iv).

Aluminum: Soft metal, white in color, light in weight, good electrical conductivity.

v).

Gun metal: Alloy of copper, tin and zinc, used in making casting.
TOOLS USED IN FITTING SHOP

CLAMPING TOOLS
Clamping tools are used for holding the job firmly during various fitting operations.
i).

Bench vice: It is a common tool for holding the jobs. It consists of cast iron body and
iron jaws .The jaws are opened up to required length, job is placed in the jaws and is fully
tightened with handle.

ii).

Leg vice: It is stronger then bench vice and used for heavy work.

iii).

Hand vice: It is used to grip very small objects.

iv).

Pin vice: Pin vice is used to hold wire or small diameter rods.

v).

Pipe vice: It is used to hold pipes. It grips the pipe at four places and is fixed on bench or
can be grouted.

MEASURING AND MARKING TOOLS
i).

Try Square: It is used for checking square ness of two surfaces. It consists of a blade
made up of steel, which is attached to base at 90°.

ii).

Bevel Protector: It consists of a steel dial divided into 360° divisions, used for
measuring angles.

iii).

Combination Set – Multipurpose instrument can be used as a protector, a level, a meter,
a center square and a Try square.

iv).

Centre Square – It is used to find the centre of the round jobs, Angle of punching end is
60°.

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v).

Scriber and Surface Gauge – It is used for marking of lines parallel to a surface. Scriber
mounted on a vertical bar is called surface gauge.

vi).

Dot Punch – It is used for marking dotted lines. Angle of punching end is 60°.

vii).

Centre Punch – It is like a dot punch used to mark the centre of hole before drilling.
Angle of punch end is 90°.

viii).

Surface Plate – Surface plate is used for testing the flatness, trueness of surfaces; its
upper face is planed to form a very smooth surface.

ix).

Angle Plate – It consists of cast iron in which two ribs of metal are standing at right
angle to each other, used for holding and supporting the jobs.

x).

‘V’ Block – It is used for supporting as well as marking of round jobs.

xi).

Steel Rules – It is made up of stainless steel and marked in inches or millimeters,
available in various sizes ½ ft to 3 ft.

xii).

Vernier Caliper – It is a precision instrument used for measuring lengths and diameters.
Minimum dimension that can be expressed on Vernier caliper is known as least count,
which is usually 0.001 or 0.02 mm.

xiii).

Micrometer – It is used for measuring diameters or thickness of any Job. The graduation
on micrometers is available in inches as well as in millimeters.

xiv).

Dial Indicator – A round gauge in which a pointer moves over a graduated scale. The
movement is magnified through links. It is used to check the run out or ovality of Jobs.

xv).

Dividers – Dividers have two legs having sharp feet. It is used for marking arcs, dividing
a line or transferring the dimensions.

xvi).

Calipers: it is generally used to measure the inside or outside diameters. There are four
types of calipers.
a) Outside calipers
b) Inside calipers
c) Spring calipers
d) Odd leg calipers

xvii)

Gauges
i).Depth Gauge: It is used to measure the depth of a hole. The beam is graduated in
inches or millimeters.
ii).Feelers Gauge: It is used to check the gap between two mating parts. It consists of a
number of metal leaves of different thickness marked on the leaves.
iii).Radius Gauge: It is used to check the radius of outer and inner surfaces. Every leave
has different radius.
iv).Vertical Height Gauge: It is used to measure the height of work pieces.
v).Thread Gauge: It is used to check the pitch of the threads. It consists of a number of
leaves, pitch of the threads marked on each leaves.
vi).Wire Gauge: It is used to check the diameter of wires and thickness of sheets.

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CUTTING TOOLS
These tools are used to remove the materials
1. Hacksaw – It is used of cutting of flats, rods etc. The blade of hacksaw is made up of high
carbon steel and frame is made from mild steel. The blade is placed inside the frame and is
tightened with the help of a flange nut. The teeth of hacksaw blades are generally forward
cut. There are two types of hacksaw frames, fixed frames and adjustable frame. The material
to be cut with hacksaw is clamped in a vice. The hacksaw should be moved perfectly straight
and horizontal.
2. Files – It is used to remove material by rubbing it on the metal. Classification of files.
i)
Size – The length of file vary from 4 inch to 14 inch.
ii)
Shape – The shapes available are flat, square, round, half-round, triangular etc.
iii)
Cuts – Single and Double Cut.
iv)
Grade –
Rough - 20 Teeth per inch
Bastard - 30 Teeth per inch
Second Cut - 40 Teeth per inch
Smooth – 50-60 Teeth per inch
Dead Smooth - 100 Teeth per inch
Rough and Bastard files are used for rough cutting, smooth and dead smooth files are
used for finishing work. Files should be used in perfect horizontal position. Pressure
should be applied on the forward stroke only. Work is held in a vice.
3. Chisels – They are used for chipping away the material from the work piece. Commonly
used forms of chisels are flat, cross cut, half round, and diamond point chisels. Flat chisel is
used for chipping a large surface. Crosscut chisel is used for groover. Half round chisel is
used to cut oil-grooves. Diamond point chisel is used for chipping plates.
STRIKING TOOLS
Hammers are the only tools used for striking in fitting shop like chipping, fitting, punching etc.
Main types of hammer
1.
Ball Pean Hammer
2.
Straight Pean Hammer
3.
Cross Pean Hammer
MISCELLANEOUS TOOLS
1.

Drill Bit– It is used for making round holes. Twist drill is most commonly used for making
holes.

2.

Reamer – It is used to finish the drilled hole to accurate size.

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Taps – It is used for making internal threads. The tap holder holds tap, normally it comes in a
set of three, taper Tap, Intermediate Tap, Plug Tap.
Die – It is used for cutting external threads. It is held in a diestock, the handle is rotated by
hand and job is held firmly in a vice.

BENCH WORKING PROCESSES
1. Marking – Measurement is performed on the job by measuring instrument and scriber does
marking.
2. Chipping – Material is removed with the help of chisels.
3. Sawing – This operation is required to cut the metal in different sizes and shapes by
hacksaw.
4. Filing – This operation is performed with the help of files, pressure should be exerted in the
forward stroke and backward stroke is ideal.
5. Scrapping – This is done for reducing more accurate finish that obtained by filing.
6. Drilling – This is done to produce holes with the help of drills. It is done on a drilling
machine and job is held in a machine vice. Drill is fixed on the drilling machine,
7. Tapping – This is done to cutting the internal threads with the help of tap and tap holder.
8. Dieing – This is done to cut the external threads by the help of die and die holder.
DRILLING MACHINES
There are three types of drilling machines:
1. Bench Drilling Machine: It is used for drilling, reaming, counter sinking and counter boring
etc.
2. Hand Drilling Machine: It is used for making small holes. It is pressed from the handle with
left hand while crank is rotated with right hand.
3. Portable Drilling Machine: It is compact and small in size; it can be brought near to the
work place for drilling medium size holes.

4. Radial Drilling Machine: It is used for drilling large size holes, can be moved in different
directions.
SCREW THREADS
(i) British standard Whitworth threads (BSW): The thread is generally used on bolts and
nuts ‘V’ shape having an angle of 60º.
(ii) Metric Threads: ‘V’ shape having an angle of 60º.
(iii)Square Threads: Shape of thread is square used on screw jacks.
(iv) Acme Threads: These threads are stronger than square threads having an angle of 29º, they
are used on lead screw shaft of Lathe.

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To Make Right Angle Fitting Job
1. Objective: - Exercise involving marking, Cutting, Filing, Drilling, Chipping and Tapping on a
M.S. Flat.
2. Tools and equipment used: - Bench vice, Hacksaw. Files. Scriber, Steel rule, Try square,
Hammer, Chisel Flat, Surface plate, Angle Plate, Surface gauge, Drills, Taps, Vernier caliper,
Centre punch, Drilling machine.
3. Materials required: - Mild steel flat 62 x 6 mm.
4. Drawing: - See Diagrams
5. Procedure:Ex I: - To make Rectangular job 60 x 40 mm.
1.
2.
3.
4.
5.

Mark the M.S flat 62 x 6 x 42 mm (Two pieces) and cut the metal pieces with Hacksaw,
clamping in a Bench vice.
File the two sides at right angle, check with try square.
Mark the other two sides with surface gauge on a surface plate supporting by angle plate to
dimension 60 x 40 mm.
Cut extra metal and file to accurate 60 x 40 mm rectangular piece. Finish the surface with
smooth file keeping tolerance ± 0.5 mm; check the dimension with vernier caliper.
Finish the other piece also by same procedure.
Ex II: - To make a part 1

1.
2.
3.

1.
2.
3.

Mark parallel lines at 20 mm distance on a finished rectangular piece of 60 x 40 mm as shown
in diagram.
Cut with hacksaw outer side of marked lines to remove 20 mm square pieces on both sides.
File the cut ‘T’ to bring it to accurate dimensions, check all angles at 900 with try square.

Ex III: - To make a part 2
Mark parallel lines at 20 mm distance on another finished rectangular piece 60 x 40 mm.
Punch mark at equal distance Drill 3.5 mm hole, Cut with Hacksaw inside line of
marking
and chip out 20mm piece with a chisel as shown in diagram
File the cut to bring it to accurate dimensions, check angles with try square.

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Ex IV: - Fitting of part 1 into part 2

1.
2.
3.

Fit the Part 1 into Part 2 after filing to accurate dimension of fitting clearance
0.1 mm.
Check for square ness of the fitting male & female parts.
Finish the job with a smooth file.

Ex V: - To make internal Threads

1.
2.
3.
4.
5.

Mark the point with centre punch, drill hole (6.8 mm for 8 x 1.25 mm) tapping as shown in
diagram.
Fix the taper tap in a Tap Holder, Clamp the Job in a bench vice, Insert Tap in a drilled hole,
hold perpendicular and rotate chock wise to start threading.
Apply little Lubricating oil on cutting operation, on each half turn forward, Turn the tap
backward quarter turn, to break the cutting chips.
Repeat with threading operation with intermediate and finally with bottoming Tap.
Remove the burrs with a file.

Safety Precaution
1.
2.
3.
4.
5.
6.
7.
8.
9.

Grip the Job in the vice properly.
Always move the hacksaw in perfect straight and horizontal position.
Hacksaw blade should the fixed in proper direction and tightened sufficiently with correct
tension.
Use water as a coolant while sawing.
Hold the chisel firmly while chipping
Drill the holes centralizing on pop Marks, give gradual feed.
check the dimension time to time carefully, check with Try square and vernier cliper.
Tap should be held perpendicular and rotated every half turn forward, reverse quarter turn,
backward.
Use lubricating oil during tapping.

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TO MAKE A RIGHT ANGLE FITTING JOB

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EX: 1

EX: 2

PART: 1

EX: 3

PART: 2

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EX: 4

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EX: 5

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TO MAKE A RIGHT ANGLE FITTING JOB

All dimensions in mm
Material : M.S. Flat 62×6 mm
Tolerances ± 0.5 mm

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1. Objective: To carry different types of fitting operations like checking, marking, punching,
cutting filing etc. on a job of size 50*60 mm MS flat
2. Tools & Equipment Use: File, Hacksaw, bench vice, Twist drill, drilling machine, surface
plate, angle plate, marking gauge, Vernier clippers, Try square
3. Material Required: Mild steel flat 50*62*6 mm
4. Drawing: See diagram
5. Procedure:
1.

Check the tools and equipments required to ensure that the required tools are in good
working condition.

2.

Do marking on the MS Flat using scale and cut the piece with the help of hacksaw.

3.

Do filing operation on the job piece with proper method of filing and make two sides
at a right angle.

4.

Do marking operation with the marking tools and cut a chamfer cut 10*10 mm and
square cut of 15*15 mm by using hacksaw.

5.

Do drilling operation with the pillar electric drilling machine and do the tapping
operation.

6.

Do finishing operation with smooth file.

6. Precaution:
1.

Grip the job in the bench vice properly.

2.

Always move the hacksaw in perfect and straight horizontal position.

3.

The blade should be tight to avoid breaking.

4.

The teeth should be protected from excessive wearing.

5.

tapping should be at right angle

6.

keep your hands away from the drilling machine

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To make a square fitting job

Material : M.S. Flat 62.6 mm
Tolerance: ±0.5 mm

____________________________________________________________________________

Manufacturing Practice - Lab Manual - B.Tech. - Mechanical Engineering

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Manufacturing Practice - Lab Manual - B.Tech. - Mechanical Engineering