FOUNDRY FORGING AND WELDING LABORATORY 2022 PART B.pdf

FOUNDRY, FORGING & WELDING LAB (18MEL38B/48B), by – Dr. S B MALLUR, Professor, UBDTCE, Davanagere 1
Mechanical Engineering Department
University B.D.T College of Engineering, Davangere
(A Constituent College of V.T.U, Belgaum)
LAB MANUAL
III/IV Semester
FOUNDRY, FORGING AND WELDING
LABORATORY
(18MEL38B/48B)
Name:_________________________________________
U.S.N:_________________________________________
Batch:________________ Section:________________
Dr. S B MALLUR
Professor
Mechanical Engineering Department

CONTENTS
UNIT – 1
TESTING OF MOULD AND CORE SAND
Exp.No Title of the Experiment Page No
PART A PART A PART A
Testing of Molding sand and Core sand.
1-34
1
Testing of Molding sand and Core sand.
Compression strength test for moulding sand
Shear strength test for moulding sand
Tensile strength test of core sand
Permeability test
Core hardness and mould hardness test
Sieve analysis to find grain fineness number of base sand
Clay content test
Welding Practice:
Use of Arc welding tools and welding equipment
Preparation of welded joints using Arc Welding equipment
L-Joint, T-Joint, Butt , V-Joint, Lap joints on M.S. flats
35-61
PART B PART B PART B
Foundry Practice:
2
Foundry Practice:
Use of foundry tools and other equipment for Preparation of molding sand
mixture.
Preparation of green sand molds kept ready for pouring in the following cases:
4. Using two molding boxes (hand cut molds).
5. Using patterns (Single piece pattern and Split pattern).
6. Incorporating core in the mold.(Core boxes).
• Preparation of one casting (Aluminium or cast iron-Demonstration only)
62-
Foundry -Introduction
Core and Core Making
Solid Pattern
Hand Cutting
Self-Cored Pattern
Stepped Cone Pulley with Core Print
Split Pattern with Two Halves
PART C PART C PART C
Forging Operations:
03
Forging Operations: Use of forging tools and other forging equipment.
• Calculation of length of the raw material required to prepare the model
considering scale loss.
• Preparing minimum three forged models involving upsetting, drawing and
bending operations.

Foundry Practice:
Foundry Practice:
Use of foundry tools and other equipment for Preparation of molding sand mixture.
Preparation of green sand molds kept ready for pouring in the following cases:
4. Using two molding boxes (hand cut molds).
5. Using patterns (Single piece pattern and Split pattern).
6. Incorporating core in the mold.(Core boxes).
• Preparation of one casting (Aluminium or cast iron-Demonstration only)
Foundry -Introduction
Core and Core Making
Solid Pattern
Hand Cutting
Self-Cored Pattern
Stepped Cone Pulley with Core Print
PART- B

FOUNDRY
Introduction:
Foundry is a process of shaping the metal components in their molten stage. It is the also called as metal
casting the shape and size of the metal casting is obtained depends on the shape and size of the cavity
produced in sand mould by using wooden/ metal pattern.
Practical application
1. Casting is the cheapest and most direct way of producing the shape of the component
2. Casting is best suited to work where components required is in low quantity.
3. Complicated shapes having internal openings and complex section variation can be produced quickly
and cheaply by casting since liquid metal can flow into any form/ shape.
Example:
1. Outer casing of all automobile engines.
2. Electric motor housing
3. Bench vice, Irrigation pumps etc.
4. Heavy equipment such as machine beds of lathe, milling machine, shaping, drilling planing machine etc.
can be cast/easily
5. Casting is best suited for composite components
Example.1. steel screw threads in zinc die casting
All conductors into slot in iron armature for electric motor.
Steps in foundry process
The Foundry process involves three steps.
(a) Making the required pattern
(b) Moulding process to produce the cavity in sand using pattern.
(c) Pouring the molten metal into the cavity to get casting.
Classification of foundries
 Steel foundry
 C.I foundry
 Light alloy foundry
 Brass foundry
 Shell moulding foundry
 Die casting foundry (using permanent metal or dies for high volume of low and pressure die)
Pattern:
A pattern is normally a wooden/ metal model or thermosetting plastic which is facsimile of the cast
product to be made, there are many types of pattern and are either one piece, two piece or three piece,
split pattern, loose piece pattern, Gated and match plate pattern etc. Pattern size: Actual casting size
+shrinkage allowance +shake allowance +finish allowance
1. Shrinkage allowance: The liquid metal shrinks during solidification and it contraction to its room
temperature, so that the pattern must be made larger then the casting to provide for total contraction.
2. Finishing allowance: The casting is to be machined at some points then the casting should be provided
with excess metal for machining.

Types of foundry sand
1. Natural sand: Sand containing the silica grains and clay bond as found. It varies in grain size and clay
content. Collected from natural recourses.
2. Synthetic sand: It is an artificial sand obtained by mixing relatively clay free sand, binder (water and
bentonoite). It is better moulding sand as its properties can be easily controlled.
3. Facing sand: It is the fine grade sand used against the face of the pattern and finally governs the
surface finish of the casting.
4. Parting sand: It is fine dry sand + brick dust used to preserve the joint face between the cope and the
drag.
Natural Green sand= sand + clay + moisture
(10 to 15%) (7 to 9%)
Synthetic Green sand= sand + clay + moisture
(5 to 7%) (4 to 8%)
5. Green sand: mouldings is the most common moulding process
5. Dry sand mould: Dry sand mould refer to a mould which is artificially dried before the molten metal is
poured into it. Dry sand moulds are costly, stronger, used for complicated castings, i.e. avoid casting
defects, casting gets smoother surface.
Moulding methods:
 Bench moulding: In this method the moulding is carried out on convenient bench and moulds are
relatively small.
 Floor mouldings: In this method the mouldings is carried out in medium and large moulds are
carried out on the floor.
 Plate mouldings: For large quantity production and for very heavy casting two plates may be used
with pattern.
 Pit moulding: In this method the moulding is carried out in the pits and generally very large
moulds are made.
 Machine mouldings: A machine is used to prepare moulds of small and medium. This method is
faster and gives uniform mouldings
CORE AND CORE MAKING
CORES: Cores are sand blocks they are used to make hollow portion in a casting. It is placed in a mould so
that when molten metal is poured into
the mould. This apart of mould will
remain vacant i.e. the molten metal
will not fill this part of the mould. So
when the mould is broken and the
castings removed a hollow portion will
result in the casting.
Core sand= Moulding sand+
binders (ABC core oil) or sodium
silicate
Core making: Cores are made
separately in a core box made of wood
or metal.

Core binders
1. Water soluble binders (2 t0 4% by weight)
2. Oil binders (1-3% by weight)
3. Pitch and resin binders (1-35 by weight)
The sand is treated with binder to achieve cohesion
Core Baking
The core is baked (hardened) by heating at 150C depends on core size in oven.
This hardening of the core helps to handle and to place the core in the mould.
The core is supported in the mould by projection known as core prints.
NOMENCLATURE OF A MOULD

FOUNDRY TOOLS AND EQUIPMENTS
1. INTRODUCTION
There are large number of tools and equipment used in foundry shop for carrying out different operations
such as sand preparation, molding, melting, pouring and casting. They can be broadly classified as hand
tools, sand conditioning tool, flasks, power operated equipments, metal melting equipments and fettling
and finishing equipments. Different kinds of hand tools are used by molder in mold making operations.
Sand conditioning tools are basically used for preparing the various types of molding sands and core sand.
Flasks are commonly used for preparing sand moulds and keeping molten metal and also for handling the
same from place to place. Power operated equipments are used for mechanizing processes in foundries.
They include various types of molding machines, power riddles, sand mixers and conveyors, grinders etc.
Metal melting equipment includes various types of melting furnaces such as cupola, pit furnace, crucible
furnaces etc. Fettling and finishing equipments are also used in foundry work for cleaning and finishing
the casting. General tools and equipment used in foundry are discussed as under.
2 HAND TOOLS USED IN FOUNDRY SHOP
The common hand tools used in foundry shop are fairly numerous. A brief description of the following
foundry tools used frequently by molder is given as under.
1.Showel: It consists of iron pan with a wooden handle. It can be used for mixing and conditioning the
sand.
Shovel is shown in Fig. 1(b). It consists of an steel pan fitted with a long wooden handle. It is used in
mixing, tempering and conditioning the foundry sand by hand. It is also used for moving and transforming
the molding sand to the container and molding box or flask. It should always be kept clean.
2. Trowels: These are used for finishing flat surfaces and comers inside a mould. Common shapes of
trowels are shown as under. They are made of iron with a wooden handle. Trowels are shown in Fig.
11.1(l, m and n). They are utilized for finishing flat surfaces and joints and partings lines of the mold. They
consist of metal blade made of iron and are equipped with a wooden handle. The common metal blade
shapes of trowels may be
pointed or contoured or
rectangular oriented. The
trowels are basically
employed for smoothing or
slicking the surfaces of
molds. They may also be
used to cut in-gates and
repair the mold surfaces.

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

Hand riddle is shown in Fig. 1(a). It consists of a screen of standard circular wire mesh equipped with
circular wooden frame. It is generally used for cleaning the sand for removing foreign material such as
nails, shot metal, splinters of wood etc. from it. Even power operated riddles are available for riddling
large volume of sand.
5.Strike off bar: It is a flat bar, made of wood or iron to strike off the excess sand from the top of a box
after ramming.
Its one edge made beveled and the surface perfectly smooth and plane.
6. Vent wire: It is a thin steel rod or wire carrying a pointed edge at one end and a wooden handle or a
bent loop at the other. After ramming and striking off the excess sand it is used to make small holes,
called vents, in the sand mould to allow the exit of gases and steam during casting.

7. Rammers: Rammers are used for striking the sand mass in the moulding box to pack it closely around
one pattern. Common types of rammers are shown as under.
Rammers are shown in Fig. These are required for striking the molding sand mass in the molding box to
pack or compact it uniformly all around the pattern. The common forms of rammers used in ramming are
hand rammer, peen rammer, floor rammer and pneumatic rammer which are briefly described as
8. Swab: It is a hemp fiber brush used for moistening the edges of sand mould, which are in contact with
the pattern surface, before withdrawing the pattern. It is also used for coating the liquid blacking on the
mould faces in dry sand moulds.
9. Sprue 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.
Sprue pin is shown in Fig. It is a tapered rod of wood or iron which is placed or
pushed in cope to join mold cavity while the molding sand in the cope is being
rammed. Later its withdrawal from cope produce a vertical hole in molding
sand, called sprue through which the molten metal is poured into the mould
using gating system. It helps to make a passage for pouring molten metal in
mold through gating system

10. Sprue cutter: It is also used for the same purpose as a sprue pin, but there is a marked difference
between their use in that the cutter is used to produce the hole after ramming the mould. It is in the form
of a tapered hollow tube, which is inserted in the sand to produce the hole.
Strike off bar
Strike off bar (Fig. is a flat bar having straight edge and is made of wood or iron. It is used to strike off or
remove the excess sand from the top of a molding box after completion of ramming thereby making its
surface plane and smooth. Its one edge is made beveled and the other end is kept perfectly smooth and
plane.
Mallet
Mallet is similar to a wooden hammer and is generally as used in carpentry or sheet metal shops. In
molding shop, it is used for driving the draw spike into the pattern and then rapping it for separation from
the mould surfaces so that pattern can be easily withdrawn leaving the mold cavity without damaging the
mold surfaces.
Draw spike
Draw spike is shown Fig. It is a tapered steel rod having a loop or ring
at its one end and a sharp point at the other. It may have screw
threads on the end to engage metal pattern for it withdrawal from the
mold. It is used for driven into pattern which is embedded in the
molding sand and raps the pattern to get separated from the pattern
and finally draws out it from the mold cavity.

Vent rod
Vent rod is shown in Fig. 11.1(g). It is a thin spiked steel rod or wire carrying a pointed edge at one end
and a wooden handle or a bent loop at the other. After ramming and striking off the excess sand it is
utilized to pierce series of small holes in the molding sand in the cope portion. The series of pierced small
holes are called vents holes which allow the exit or escape of steam and gases during pouring mold and
solidifying of the molten metal for getting a sound casting.
Lifters
Lifters are shown in Fig.. They are also known as cleaners or finishing tool which are made of thin sections
of steel of various length and width with one end bent at right angle. They are used for cleaning, repairing
and finishing the bottom and sides of deep and narrow openings in mold cavity after withdrawal of
pattern. They are also used for removing loose sand from mold cavity.
Slicks
Slicks are shown in Fig. 11.1(o, p, q, and r). They are also recognized as small double ended mold finishing
tool which are generally used for repairing and finishing the mold surfaces and their edges after
withdrawal of the pattern. The commonly used slicks are of the types of heart and leaf, square and heart,
spoon and bead and heart and spoon. The nomenclatures of the slicks are largely due to their shapes.

Smoothers
Smothers are shown in Fig. 11.1(s and t). According to their use and shape they are given different names.
They are also known as finishing tools which are commonly used for repairing and finishing flat and round
surfaces, round or square corners and edges of molds.
Spirit level
Spirit level is used by molder to check whether the sand bed or molding box is horizontal or not.
Gate cutter
Gate cutter (Fig. 11.1(v)) is a small shaped piece of sheet metal commonly used to cut runners and
feeding gates for connecting sprue hole with the mold cavity.
Gaggers
Gaggers are pieces of wires or rods bent at one or both ends which are used for reinforcing the
downward projecting sand mass in the cope are known as gaggers. They support hanging bodies of sand.
They possess a length varying from 2 to 50 cm. A gagger is always used in cope area and it may reach up
to 6 mm away from the pattern. It should be coated with clay wash so that the sand adheres to it. Its
surface should be rough in order to have a good grip with the molding sand. It is made up of steel
reinforcing bar.
Spray-gun
Spray gun is mainly used to spray coating of facing materials etc. on a mold or core surface.
Nails and wire pieces
They are basically used to reinforce thin projections of sand in the mold or cores.
Wire pieces, spring and nails

They are commonly used to reinforce thin projections of sand in molds or cores. They are also used to
fasten cores in molds and reinforce sand in front of an in-gate.
Clamps, cotters and wedges
They are made of steel and are used for clamping the molding boxes firmly together during pouring.
FLASKS
The common flasks are also called as containers which are used in foundry shop as mold boxes, crucibles
and ladles.
1. Moulding Boxes
Mold boxes are also known as molding flasks. Boxes used in sand molding are of two types:
(a) Open molding boxes. Open molding boxes are shown in Fig. They are made with the hinge at one
corner and a lock on the opposite corner. They are also known as snap molding boxes which are generally
used for making sand molds. A snap molding is made of wood and is hinged at one corner. It has special
applications in bench molding in green sand
work for small nonferrous castings. The
mold is first made in the snap flask and then
it is removed and replaced by a steel jacket.
Thus, a number of molds can be prepared
using the same set of boxes. As an
alternative to the wooden snap boxes the
cast-aluminum tapered closed boxes are
finding favor in modern foundries. They
carry a tapered inside surface which is
accurately ground and finished. A solid
structure of this box gives more rigidity and
strength than the open type. These boxes
are also removed after assembling the
mould. Large molding boxes are equipped
with reinforcing cross bars and ribs to hold
the heavy mass of sand and support gaggers.
The size, material and construction of the
molding box depend upon the size of the
casting.
(b) Closed molding boxes. Closed molding boxes are shown in Fig. 11.3 which may be made of wood,
cast-iron or steel and consist of two or more parts. The lower part is called the drag, the upper part the
cope and all the intermediate parts, if used, cheeks. All the parts are individually equipped with suitable
means for clamping arrangements during pouring. Wooden Boxes are generally used in green-sand
molding. Dry sand moulds always require metallic boxes because they are heated for drying. Large and
heavy boxes are made from cast iron or steel and carry handles and grips as they are manipulated by
cranes or hoists, etc. Closed metallic molding boxes may be called as a closed rectangular molding box

(Fig. 11.3) or a closed round molding box (Fig. 11.4).
Ladle
It is similar in shape to the crucible which is also made from graphite or steel shell lined with suitable
refractory material like fire clay. It is commonly used to receive molten metal from the melting furnace
and pour the same into the mold cavity. Its size is designated by its capacity. Small hand shank ladles are
used by a single foundry personal and are provided with only one handle. It may be available in different
capacities up to 20 kg. Medium and large size ladles are provided with handles on both sides to be
handled by two foundry personals. They are available in various sizes with their capacity varying from 30
kg to 150 kg. Extremely large sizes, with capacities ranging from 250 kg to 1000 kg, are found in crane
ladles. Geared crane ladles can hold even more than 1000 kg of molten metal. The handling of ladles can
be mechanized for good pouring control and ensuring better safety for foundry personals workers. All the
ladles consist of an outer casing made of steel or plate bent in proper shape and then welded. Inside this
casing, a refractory lining is provided. At its top, the casing is shaped to have a controlled and well
directed flow of molten metal. They are commonly used to transport molten metal from furnace to mold

PROBABLE CAUSES AND SUGGESTED REMEDIES OF VARIOUS CASTING DEFECTS
The probable causes and suggested remedies of various casting defects is given in Table 5.1.
Table 5.1: Probable Causes and Suggested Remedies of Various Casting Defects
SL.
No
Name of Casting
Defect
Probable Causes Suggested Remedies
01 Blow holes 1. Excess moisture content in molding sand.
2. Rust and moisture on Chills,
chaplets and inserts
3. Cores not sufficiently baked.
4. Excessive use of organic binders.
5. Molds not adequately vented.
6. Molds rammed very hard.
1. Control of moisture content.
2. Use of rust free chills, chaplet
and clean inserts.
3. Bake cores properly.
4. Ram the mold s less hard.
5. Provide adequate venting in
mold and cores
Fig.
02 Shrinkage Shrinkage faults are faults caused by improper directional solidifications, poor
gating and risering design and inadequate feeding.
1. Faulty gating and risering system.
2. Improper chilling.
1. Ensure proper directional
solidification by modifying gating,
risering and chilling

03 Porosity This is porosity caused by gases absorbed by the molten metal. Practically all
metals absorb oxygen, hydrogen and nitrogen. Oxygen and nitrogen form
oxides and nitrides respectively. Hydrogen is responsible for causing pin hole
porosity.
1. High pouring temperature.
2. Gas dissolved in metal charge.
3. Less flux used.
4.Molten metal not properly degassed.
5. Slow solidification of casting.
6. High moisture and low permeability in
mold.
1. Regulate pouring temperature
2. Control metal composition.
3. Increase flux proportions.
4. Ensure effective degassing.
5. Modify gating and risering.
6. Reduce moisture and increase
permeability of mold.
04 Misruns A casting that has solidified before completely filling mold cavity
A misrun is caused when the section thickness of a casting is so small or the
pouring temperature so low that the entire section is not filled before the metal
solidifies.
1. Lack of fluidity ill molten metal.
2. Faulty design.
3. Faulty gating.
1. Adjust proper pouring
temperature.
2. Modify design.
3. Modify gating system.

05 Hot Tears
1. Lack of collapsibility of core.
2. Lack of collapsibility of mold
3. Faulty design.
4. Hard Ramming of mold.
1. Improve core collapsibility.
2. Improve mold collapsibility.
3. Modify casting design.
4. Provide softer ramming.
06 Metal
penetration
If the sand grains used are very coarse or the metal poured has very high
temperature the metal is able to enter the spaces between sand grains to some
distance. Such sand becomes tightly wedged in the metal and is difficult to remove.

1. Large grain size and used.
2. Soft ramming of mold.
3. Molding sand or core has low strength.
4. Molding sand or core has high
permeability.
5. Pouring temperature of metal too high.
1. Use sand having finer grain
size.
2. Provide hard ramming.
3. Suitably adjust pouring
temperature
07 Cold Shut Two portions of metal flow together but there is a lack of fusion due to
premature freezing (fig. b).
Metal splatters during pouring and solid globules form and become entrapped in
casting (fig. c).
1. Lack of fluidity in molten metal.
2. Faulty design.
3. Faulty gating.
1. Adjust proper pouring
temperature.
2. Modify design.
3. Modify gating system
08 Cuts and
washes
Cuts and washes are caused by erosion of mould and core surfaces by the metal
flowing in the mould cavity.
1. Low strength of mold and core.
2. Lack of binders in facing and core
Stand.
3. Faulty gating.
1. Improve mold and core
strength.
2. Add more binders to facing and
Core sand.
3. Improve gating

09 Inclusions 1. Faulty gating.
2. Faulty pouring.
3. Inferior molding or core sand.
4. Soft ramming of mold.
5. Rough handling of mold and core.
1. Modify gating system
2. Improve pouring to minimize
turbulence.
3. Use of superior sand of good
strength.
4. Provide hard, ramming.
10 Fusion When the mould sand does not have enough refractoriness or the metal is
poured at very high temperature or the facing sand is of poor quality, the sand
may melt and fuse with casting surface.
1. Low refractoriness in molding sand
2. Faulty gating.
3. Too high pouring temperature of metal
4. Poor facing sand.
1. Improve refractoriness of sand.
2. Modify gating system.
3. Use lower pouring
temperature.
4. Improve quality of facing sand.
11 Drops Sand drop is also called as sand crush. The sand mold drops
part of sand blocks, so they will cause the similar shaped
sand holes or incomplete.
1. Low green strength in molding sand and
core.
2. Too soft ramming.
3. Inadequate reinforcement of sand
and core projections
1. Increase green strength of sand
mold.
2. Provide harder ramming.
3. Provide adequate
reinforcement to sand
projections and cope by using
nails and gaggers.

12 Shot Metal 1. Too low pouring temperature.
2. Excess sulphur content in metal.
3. Faulty gating.
4. High moisture content in molding sand.
1. Too low pouring temperature.
2. Excess sulphur content in
metal.
3. Faulty gating.
4. High moisture content in
molding sand.
13 Shift A step in cast product at parting line caused by sidewise relative displacement
of cope and drag
1. Worn-out or bent clamping pins.
2. Misalignment of two halves of pattern.
3. Improper support of core.
4. Improper location of core.
5. Faulty core boxes.
6. Insufficient strength of molding sand
and core.
1. Repair or replace the pins, for
removing defect.
2. Repair or replace dowels which
cause misalignment.
3. Provide adequate support to
core.
4. Increase strength of both mold
and core
14 Crushes 1. Defective core boxes producing
over-sized cores.
1. Repair or replace the pins,
for removing defect.

2. Worn out core prints on patterns
producing under sized seats for cores
in the mold.
3. Careless assembly of cores in the mold
2. Repair or replace dowels which
cause misalignment.
3. Provide adequate support to
core.
and core.
15 Rat-tails or
Buckles
1. Continuous large flat surfaces on
Casting.
2. Excessive mold hardness.
3. Lack of combustible additives in
molding sand.
1. Break continuity of large flat
groves and depressions
2. Reduce mold hardness.
3. Add combustible additives to
sand.
16 Swells 1. Too soft ramming of mold.
2. Low strength of mold and core
3. Mold not properly supported.
1. Provide hard ramming.
and core.
17 Hard Spot 1. Faulty metal composition.
2. Faulty casting design.
1. Suitably charge metal
composition.
2. Modify casting design.
18 Run out, Fin
sand Fash
1. Faulty molding.
2. Defective molding boxes.
1. Improving molding technique.
2. Change the defective molding
boxes
3. Keep weights on mold boxes.
19 Spongings 1. Availability of dirt and swarf held
in molten metal.
2. Improper skimming.
3. Because of more impurities in
molten metal
1. Remove dirt swarf held in
molten metal.
2. Skimming should be perfect.
3. Fewer impurities in molten
metal should be there.
20 Warpage 1. Continuous large flat surfaces on
Castings indicating a poor design.
2. No directional solidification of casting
1. Follow principle of sufficient
directional solidification
2. Make good casting design
DEFECT ANALYSIS OF CASTINGS
Reasons for Casting Rejections
Casting Failed
Pressurized
Leak Test
(28%)
Visual
Imperfection on
Machined
Surface (52%)
Casting
Breakage
During
Machining
(16%)
Low Tool Life
& Excessive
Machined
Surface
Roughness
(4%)
Defects Causing Surface Imperfection (relative
frequency of each defect found)
Flow Lines
(7.7%)
Cold Laps
(46%)
Lubricant or
Mold Coating
Inclusions on
Surface (16%)
Gas Porosity
(85%)
Shrinkage
Porosity (69%)
Oxide
Inclusions
(38%)

Working steps in making the sand casting
1. Place the pattern on the turn overboard.
2. Place the drag around the pattern with upside and sprinkle the parting sand at the bottom.
3. Fill the Moulding sand over the pattern pack, Ram, Jolt &squeeze.
4. Level the bottom drag surface by leveller& turn over the drag.
5. Sprinkle the parting sand, place the cope on the drag to suit the drag slot.
6. Select the in and out gate in the drag, Place the sprue pins.
7. Fill the moulding sand around the sprue pins pack, Ram, Jolt and Squeeze & level the surface.
8. Make vent holes on both the boxes with the help of vent wire.
9. Remove the sprue pin & Separate cope from drag.
10. Remove the pattern carefully with the help of draw pin, Cut gate ways to flow the molten metal.
11. From the funnel shape on runner & riser, Hole to pour the molten metal on the top of the cope
box.
12. Join the two boxes with clamps, Now the mould is ready to pour the molten metal.
Defects Causing Casting Breakage at Machining
(relative frequency of each defect found)
Gas Porosity
(75%)
Cold Laps
(75%)
Shrinkage
Porosity (75%)
Oxide Inclusions
(25%)
Mechanical
Cracks (25%)

GREEN SAND MOULDING
A green sand mould is composed of a mixture of sand (silica sand SiO2), clay (act as binder), and water.
The word green is associated with the condition of wetness or freshness and because the mould is left in
the damp condition, hence the name “green sand mould”. This type of mould is the cheapest and has the
advantage that used sand is readily reclaimed. But the mould being in the damp condition, is weak and
cannot be stored for a longer period. Hence such moulds are used for small and medium sized casting.
Principal Methods of Green-sand Moulding are:
1. Open-sand method
2. Bedded-in-method
3. Turn-over method
Open-sand Method
It is simplest form of green sand moulding, particularly suitable for solid patterns. For convenience in
working and pouring, the entire mould is made in the foundry floor or in a bed of sand above floor level.
Moulding box is not necessary and the upper surface of the mould is open to air. After proper levelling
the pattern is pressed in the sand bed for making mould. Pouring basin is made at one end of the mould,
and the overflow channel cut at the exact height from the bottom face of the mould for giving necessary
thickness.
Bedded-in method
In this method, the pattern is hammered down or pressed to bed it into the sand of the foundry floor or
in a drag filled partially with sand to form the mould cavity. The sand should be rammed close to the
pattern sand; a cope is placed over the pattern. The cope is rammed up, runners and risers are cut and
the cope box is lifted. Now the pattern is withdrawn, the surfaces of drag and cope replaced in its correct
position for completing the mould.
iii) Turn-over method
One pattern-halfis placed with its flat side on a moulding board, a drag is rammed and rolled over. The
other pattern half and a cope box are placed in position. After ramming the cope is lifted off and the two
pattern halves shaken and withdrawn. Now the cope is replaced on the drag for assembling the mould.
green sand moulding processes

Steps involved in Green sand moulding
1. First one half of the pattern is placed on the moulding board.
2. The drag is placed with the dowel pins down.
3. Moulding sand is filled in the moulding box to cover the pattern.
4. The drag is completely filled with sand up to the top and rammed by the peen end of the hand
rammer.
5. Excess sand is levelled by a strike-off bar.
6. The drag is tilled upside down.
7. Parting sand is applied on the surface.
8. The other half of the pattern is how placed correctly on the already placed half
9. The cope is placed in position on the drag and aligned using dowel pins.
10. The sprue pin is placed vertically for the purpose of pouring the molten metal.
11. The risers are placed over the highest point of the pattern for the purpose of escaping the gases
and identify the level of molten metal.
12. Again the moulding sand filled in the cope box, and rammed.
13. The riser and the sprue pin are removed.
14. The funnel shaped opening called a pouring basin is cut at the top of the sprue pinhole.
15. The cope is lifted, turned over and placed on the floor.
16. The pattern pieces are carefully removed.
17. The gate is cut that is connecting the sprue basin and the mould cluity.
18. The cope is placed carefully over the drag.
19. Pouring the molten metal.
Advantages of green sand Moulding :
 Green sand moulds are softer than dry sand moulds. This allows greater freedom in construction when
the castings solidify and cool.
 Green sand moulds are quite strong for small depths, as the gases escape from them.
 Green sand moulds do not require any backing operations or equipment, but dry sand cores are to be
used.
Disadvantages of green sand moulding :
 The green sand moulds cannot be stored for long time.
 The green sand moulds are not so strong as other moulds are liable to be damaged during handling or
pouring.
 The surface finish of the casting obtained from green sand mould is not very smooth.
 The green sand mould lacks permeability and strength, which causes certain defects like blow holes
etc.

FUNDAMENTALS OF MOULD PREPARATION
The basic terms involved in preparation of moulds are illustrated & discussed briefly in Fig.3.1
Fig 3.1 Basic terms in moulding
Parting line: Also called parting surface, it is the zone of separation between cope and drag portions of
the mould in sand casting.
Sprue: It is a vertical passage through which the molten metal will enter the gate, and then into the
mould cavity
Pouring basin: It is the enlarged portion of the sprue at its top into which the molten metal is poured.
Gate/Ingate: It is a short passageway which carries the molten metal from the runner/ sprue into the
mould cavity.
Riser: A riser or feed head is a vertical passage that stores the molten metal and supplies (feed) the same
to the casting as it solidifies
Mould cavity: The space in a mould that is filled with molten metal to form the casting upon
solidification.
Core: A core is pre-formed (shaped) mass of sand placed in the mould cavity to form a hollow cavity in
castings.
Core print: It is a projection attached to the pattern to help for support and correct location of core in the
mould cavity.
Ladle: It is usually made from graphite or silicon carbide, and is used to hold molten metal during pouring.

MODEL-1
MOULD PREPARATION USING SOLID PATTERN
Aim
To prepare green sand mould using solid pattern of stepped bar profile.
Tools Required
Shovel, mould box (2 nos.), rammer, strike-off bar, trowel, lifter, gate cutter, vent rod, etc.
Procedure
a) Prepare a green sand mixture containing suitable amounts of clay and moisture.
b) Place drag box on the floor in its inverted position, and keep the solid pattern at the center of the drag
box as shown in figure 3.2 (a).
c) Sprinkle parting sand around the pattern to avoid the moulding sand from sticking to the pattern
d) Fill the green sand mixture into the mould box and ram till its top level without disturbing the pattern.
e) Remove excess sand using strike-off bar and now turn the drag box upside, so that the pattern faces at
the top as shown in figure 3.2 (b).
f) Sprinkle parting sand over the drag top surface and place the cope box on top of it.
g) Place the sprue and riser at suitable position as shown in figure3.2 (c).
h) Holding the sprue and riser pin firmly in their position, fill the cope box with green sand and ram the
mixture to obtain a rigid mould.
i) Strike off excess sand from top of the cope and remove the sprue and riser pin by rapping them with
slight pressure.
j) Vent the cope with a vent wire and roll over the cope box on the floor.
k) Eject the pattern by rapping it with low pressure and cut the gate connecting the sprue and the mould
cavity.
l) Repair the mould if any, using trovel and blow-off sand particles from the mould cavity using a bellow.
m) Place the cope over drag and make the mould ready for pouring as shown in figure3.2 (d).

Fig.3.2 Mould preparation using solid pattern
Result
The mould cavity for the stepped shaped bar is prepared and made ready for pouring.

MODEL- 2
MOULD PREPARATION USING SPLIT PATTERN
Aim
To prepare a green sand mould using split pattern of dumbbell shape.
Tools required: -
1. Molding board
2. Molding flask
3. Shovel
4. Riddle
5. Rammer
6. Strike-off bar or Strike Edge
7. Sprue pin
8. Riser pin
9. Trowel
10. Spike or Draw pin
11. Slick
12. Lifters
13. Gate cutter
14. Bellows
15. Vent rod, Shovel, mould box (2 nos.), rammer, strike-off bar, trowel, lifter, gate cutter, vent rod, etc
Material required: -
1. Molding sand
2. Parting sand
3. Dum-Bell
Sequence of operation: -
1. Sand preparation
2. Sandmixing
3. Pouring
4. Finishing
Procedure
a) Prepare a green sand mixture containing suitable amounts of clay and moisture
b) Place the drag box on the floor in its inverted position and place the flat surface of one-half of the split
pattern on the floor as shown in figure3.3 (a).
c) Sprinkle parting sand around the pattern to avoid the moulding sand from sticking to the pattern.
d) Fill the green sand mixture into the mould box and ram till its top level without disturbing the pattern
e) Remove excess sand using strike-off bar and now turn the drag box upside, so that the pattern faces at
the top as shown in figure 3.3(b).
f) Sprinkle parting sand over the drag top surface and place the cope box on top of it.
g) Place the second-half of the split pattern over the first-half and ensure that both halves of pattern are
aligned by dowel pins.
h) Sprinkle parting sand on the pattern surface, and place the sprue and riser pin at suitable positions as
shown in figure 3.3 ( c)

i) Holding the sprue and riser pin firmly in their position, fill the cope box with green sand and ram the
mixture to obtain a rigid mould.
j) Strike off excess sand from top of the cope and remove the sprue and riser pin by rapping them with
slight pressure.
k) Vent the cope with a vent wire and place the cope box on the floor in its inverted position.
l) Eject both halves of the pattern by rapping them with slight pressure, and cut the gate from the mould
cavity to connect to the sprue and riser.
m) Repair the mould if any, and blow-off sand particles from the mould cavity using a bellow.
n) Place the cope over drag and make the mould ready for pouring as shown in figure3.3(d).
Precautions:-
1. Do not get the sand too wet. Water is an enemy of molten metals.
2. Provide adequate ventilation to remove smoke and fumes.
3. Never stand near or look over the mold during the pouring because of the molten metal might be too
hot.
4. Do not shake out a casting too hastily, which may result in second and third degree burns.

Fig.3.3. Mould preparation using split pattern
Result
The mould cavity for the dumbbell shaped part is prepared and made ready for pouring.

MODEL-3
MOULD PREPARATION WITHOUT USING PATTERN
Aim
To prepare a green sand mould for the component shown in figure 3.4.
Tools Required
Steel rule, spring divider, shovel, mould box (2 nos.), rammer, strike-off bar, trowel, lifter, gate cutter,
vent rod, etc.
Fig.3.4.Front and Top views of component for Model 3
Procedure
a) Prepare a green sand mixture containing suitable amounts of clay and moisture.
b) Place the drag box on the floor and ram the sand mixture till the top of the drag box.
c) Remove excess sand using strike-off bar to form a flat level surface.
d) Finish the top surface using a trowel.
e) Using a sharp tool or vent rod, draw two diagonals on the top surface of the drag box to locate the
center point of the drag box. With this point as center and using spring divider, draw a circle of radius 60
mm (hexagon side is 60 mm) as shown in figure 3.5 (a).
f) Sprinkle parting sand all over the drag surface and place the cope box on top of the drag. Place the riser
at the center point of the mould box, and sprue at a suitable location as shown in figure 3.5 (b).
g) Holding the sprue & riser pin in position, ram the sand mixture till the top of the cope box.
h) Strike-off excess sand from top of the cope and remove the sprue and riser pin by rapping them with
slight pressure.
i) Vent the cope with vent wire and lift the cope and keep it in inverted position.
j) With the center point of the circle marked in the drag box, construct a hexagon of sides 60mm.
k) With the help of knife tool and lifter, remove the sand to a depth of 40 mm to obtain a hexagon shaped
cavity as shown in figure 3.5(c).
l) Cut the gate connecting the sprue and the hexagonal shaped cavity and finish the mould to make it ready
for pouring.

Fig.3.5 Mould preparation for model 3
Result
The mould cavity for the given component is prepared and made ready for pouring.

Estimation of Material Costs
In this chapter the material cost means the direct material cost. The frequently used materials are:
Aluminum, Copper, Gunmetal, Brass, Iron, Tin, Magnesium, Mild steel, Alloy steel & Lead etc.
The generalized procedure to calculate the Material Cost:
1. Observe the component drawings; break up the drawing into simple parts as per convenience.
2. Using formulae calculate area & Volume of each part. Scrap should be taken into account to while
calculating the volume.
3. Add the Volume of all the parts.
4. Multiply the component volume & density of material. It will be weight of the component.
Density X Volume =Weight.
5. Multiply the weight of the component with the cost of material per unit weight.
The following table gives the densities of various materials:
No. Material DensityGm/cc No. Material DensityGm/cc
1 Aluminum Cast 2.70 2. Al-wrought 2.681
3. Cast Iron 7.209 4. Wrought- Iron 7.707
5. Steel 7.868 6. Mild Steel 7.2
7. Brass-Cast 8.109 8. Brass-Wire 8.382
9. Bronze 8.7 10. Gun Metal 8.735
11. Zinc-Cast 6.872 12. Zinc Sheet 7.209
13. Copper 8.622 14. Gold 19.316
15. Lead 11.368 16. Tin 7.418
Solved Examples: Stepped Pulley:
Q. No 1. A Cast-Iron Step cone pulley is shown in the following Figure. The Density of the C.I. is 7.209
gm/cc, Material Cost is Rs.20/ kg. Calculate the mass and material cost

Solutions:
Let L, M, N, P are the different parts of the fig shown.
Total Length of the Fig.=80+80+80 = 240 mm
Now calculate the volume of Each Part:

FOUNDRY FORGING AND WELDING LABORATORY 2022 PART B.pdf

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