Foundry Shop and tools

Foundry Shop and tools

The place where jobs are prepared by melting and pouring the molten metal into moulds is known asfoundry. 

A mould is a cavity so prepared that it can be used to make castings by molten metal into it. 

Pattern is a model of anything which is used to prepare moulds by placing it in sand. 

The molten metal poured into mould, on cooling is known as castings. 

The capacity of a metal to get forge is called forgability.

TOOLS USED IN FOUNDRY SHOP

Shovel: 

It consists of iron pan with a wooden handle. It can be used for mixing and conditioning the sand and then transferring the mixture in some container.

Trowels: 

These are used for finishing flat surfaces and corners inside a mould. They are made of iron with a wooden handle.

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 moulds.

Hand riddle: 

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

Strike off bar: 

It is a flat bar, made of wooden or iron to strike off the excess sand from the top of a box after ramming. It’s one edge made bevelled and the surface perfectly smooth and plane.

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.

Draw spike: 

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

Rammers: 

Rammers are used for striking the sand mass in the moulding box to pack it closely around one pattern. Peen rammer it consists of a metallic rod with a projection in the front, it is used in packing the sand at the corners of the boxes. Floor rammer it consists of a long steel bar with a peen in the front portion. It is heavier in weight and used in floor moulding for ramming and in very large moulds. Hand rammer, one end is called peen and the other end is called butt. It is used in bench moulding. 

Slicks: 

They are used for repairing and finishing the mould surfaces and the edges after the pattern has been withdraw. The commonly used slicks are heart and leaf, square and heart, spoon and bead and heart and spoon. The above nomenclature of slicks is largely due to their shapes.

Smoothers and corner slicks: 

They are also finishing tools used for repairing and finishing flat and round surfaces, round or square corners and edges. These tools find a special favor in dry sand and loam sand work.

Mallet: 

It is similar wooden mallet as that used in the carpentry work. In foundry work it is used for driving the draw spike into the pattern and then rapping it.

Swab: 

It is a hemp fibre brush used for moisturizing 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.

Spruce 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.

Spruce cutter:

 

It is also used for the same purpose as that of spruce 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 a hole.

Clamps, cotters and wedges: 

They are made of steel and are used for clamping the moulding boxes firmly together during pouring.

Nails and wire pieces: 

They are used to reinforce their projections of the sand in the mould or cores made in two halves.

Bellow: 

It is used to blow the loose or unwanted sand from the surface and the cavity of the mould.

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 tapered holes.

Pyrometer: 

It is a device which is used to measure the temperature of molten metal from the burner.

Moulding boxes or flasks: 

The moulding boxes or flasks used on sand moulding are of two types:
a. CLOSED MOULDING BOXES
b. OPEN TYPE OF SNAP FLASKS

These boxes are used in sand moulding may be made of wood, cast iron or steel. They consist two or more parts. The lower part is called drag and the upper part is called cope and all the intermediate parts (if used) is called cheeks. All the parts are individually equipped with suitable means for clamping during pouring.

Wooden flasks are generally used in green sand moulding. Dry sand moulds always requires 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. The closed metallic flasks may have a rectangular or round shape.

A snap flask is hinged in one corner and it is rectangular in shape and it is made of wood. It is used for bench moulding and number of moulds can be made from same set of flask.

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 20Kg.

Medium and large size ladles are provided with handles on both sides to be handles by two moulders. They are also made in different sizes with their capacity varying from 30-150Kg. 

Extremely, large sizes with capacities ranging from 250-1000Kg are found in crane ladles can hold even more than 1000Kg of molten metal. They facilitate a better pouring control than the ungeared ladles and ensure more safety for workers.

All the ladles, irrespective of their sizes, consist of an outer casing made of steel or plate bent in proper shape and then welded. Inside this casing is provided a refractory lining. At its top the casing is shaped to have a controlled and well directed flow of molten metal.

Crucibles: 

They are made 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. 

In oil fired tilting furnaces they form an integral part of the furnace itself and the charge is put into them while they are in position. After melting of metal, the crucibles placed in coke-fired furnaces are taken out and received in handles. Pouring is generally done directly by them instead of transferring the molten metal to ladles. But in the case of an oil fired furnaces the molten metal is first received in a ladle and then poured into the mould.

Forging tools & Equipment

Forging tools & Equipment

Furnace or hearth: 

A black smith uses a furnace for heating the metal pieces. Furnace consists of four legs, a cast iron or steel body, iron bottom, a chimney and a blower. The main parts of forging furnace are as:

a. HEARTH: 

The iron bottom where fire is lightened is known as hearth. It is provided with fire brick lining.

b. TUYERE: 

A pipe containing from the bottom or rear of the hearth is known as tuyere. It is used to supply the air at high pressure.

c. HOOD: 

The upper part of furnace is called hood. It is made up of mild steel sheet with the fire brick inside it.

d. CHIMNEY: 

Chimney is fitted on the upper end of the hood. It is used for the purpose of easy escaping of exhaust gases and smoke.

e. WATER TANK: 

A small iron tank is attached with the hearth of the furnace. It is used for dipping purposes.

EQUIPMENT USED IN FORGING

Shovel: 

It is used to place the coal into the furnace hearth.

Blower: 

It is used to supply air at high pressure to the hearth.

Poker: 

It is a bent rod used to strike the fire. Poker is made up of mild steel.

Regulator: 

It is used to control the air supply of air to the hearth. Air supply is controlled by increasing or decreasing the passage of air.

Anvil: 

A block on which forging work is done is known as anvil. It is made up of cast iron, steel or wrought iron. It acts as a supporting device for all forging operations since it is capable of withstanding very heavy blows. The anvil is supported either on a iron base, or wooden block or mounted on the foundation. Weight of the anvil varies from 100-150Kg. It is available in many sizes and shapes. 

Common type of anvil used in forging shop has the following parts:
a. Body
b. Horn
c. Chipping block
d. Face
e. Hardie hole
f. Round hole
g. Tail
h. Stand

The centre part is known as body. The projected end is called horn. It is used for making circular jobs. A steel plate riveted on the body is called face. Most of the work is done on face. Chipping block is used for cutting purposes. Holes are used for chisels or punches. At the bottom four legs are attached.

Hammer: 

Hammers are used as striking tools. These are classified as:
a. Hand hammer.
b. Sledge hammer
c. Power hammer

Hand hammer is light in weight used by the smith himself. 
Sledge hammer is heavier in weight and is used by the smith’s helper. All the hammers are divided into four parts namely pean, eye, cheeks and face. Hand hammers are of four types based on shape of the pean. If the pean is along the axis of the handle then it is straight pean hammer when the pean is across the axis of handle then it is called cross pean hammer. In case shape of the pean is same as shape of the face then it is double ended. If the shape of the pean is spherical then it is ball pean hammer. The weight of hand hammer varies from 1-2Kg and that of sledge hammer is 3-8Kg. 

When the quantity of jobs to be produced is more, power hammers are used. Commonly used hammers are spring hammers, pneumatic hammers, steam hammers and drop hammers. 
Power hammers are generally driven by electrical power. The job to be produced is placed on the anvil of the hammer. with the help of lever the weight is allowed to fall on the job. The factors which influence the working of the hammer are:
• Size and shape of the job
• Falling weight of the hammer
• Height of falling weight

Tongs: 

Tongs are used for holding and turning hot metal pieces. Depending upon their use, tongs are classified into many types. All types of tongs have similar construction except the mouth. A tong has two legs riveted from a suitable place. These are made up of mild steel. It is made in two pieces and both the pieces are joined by hinges. The length of the tongs varies from 12” to 18”. It is classified based on the shape of the mouth of the tongs.

Chisels: 

Chisels are used for cutting metal pieces in hot and cold state. Chisels are divided into following categories:
a. Hot chisel
b. Cold chisel
c. Hardie set
Hot chisel is used to cut the metal in hot state and cold chisel to cut the material in cold state. Main difference between these chisels is the cutting angle. In hot chisel cutting angle is 30 degree and in case of cold chisel 60 degree. A hardie set consists of three parts:
a. Shank
b. Body
c. Cutting edge

The shank is fitted into the hardie hole in the anvil. Chisels and the hardie set are made from carbon sheets. It is hardened upto the desired level with proper tempering.

Punches and drifts: 

Punches are made up of high carbon steel and are used for making rough holes in hot metal pieces. Punches are available in different sizes but have a common shape. A drift is a large sized punch used to enlarge a hole.

Flatters: 

As indicated by name, flatters are used to flatten the work piece. It has a plane face joined with a straight shank. It is held in a wire. The material of the flatter is high carbon steel. The body of a flatter is square in cross section.

Fullers: 

Fullers are used for grooving and drawing. These are made in two pieces (lower and upper). Lower part is mounted on the anvil and the upper is held in hand from a wire handle. These are made from high carbon steel and medium carbon steel. These are for hot work only.

Swages: 

Swages are used for giving various shapes to the work pieces. These are made up of high carbon steel and are used in two pieces as in case of fullers.

Swage block: 

It is a cast iron or cast steel rectangular block having a number of holes in it. Holes are made in different sizes and shapes. Its outer sides are also made in sectional forms to receive various types of jobs. It is always plane on a cast iron frame.

Set hammers: 

Set hammers have similar shapes as that of flatters. These are used for making the surface plane, forming and making corners. It is made of tool steel. The job is supported on the anvil and set hammer is hammered on it.

Clamping vice: 

Leg vice is only clamping device used in smithy shop. It is mounted with the table or wooden base. It consists of two jaws, a spring and a leg. Hot work pieces are clamped in it while working.

Bick iron: 

It is also made of tool steel and it is hardened. It’s one portion is similar to the horn of the anvil and a tapered tail on the other side. Due to a taper shank it is fitted in the anvil. 

PRECAUTIONS WHILE USING FORGING TOOLS AND EQUIPMENT

The following points must be kept in mind while working with the forging tools:
1. Hearth should be lightened is proper way.
2. Hammering should not be done in lazy mood.
3. Heavy blows should not be given on the tail of the anvil.
4. Hammers should have proper handle length.
5. Length of the tong should be kept between 15” to 18”. The tong should be kept cool while working with it.
6. Blunt chisels should not be used in the forging shop.
7. Mushroom should not remain on the face of the flatter, punch or chisel.
8. Never use fullers and swages for cold metal.
9. While working on furnace, keep the fire small but deep.
10. Do not let the fire burn hollow.
11. Keep the fire clear from clinkers, particularly while welding.
12. Do not add fresh coke on the top of the fire, put it at the side and pull in later when required.