Mechanical Engg Workshop Lab Manual Carpentry

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Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 ME-104 MANUFACTURING PRACTICE L T P Maximum Marks: 100 1 - 6 Internal: 40 External: 60 PART-A 1.

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. 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. Jain, R.K.; Production Technology, Khanna Publishers, New Delhi. Singh, S,; Manufacturing Practice, S.K. Kataria & Sons, New Delhi. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 SAFETY PRECAUTIONS CARPENTRY SHOP 1.

While working keep your mind & eyes on the job & do not indulge in talking. Avoid using loose clothing.

There should be no sharp tools in your pocket. The tools being used should be well sharpened. The floor of the shop should be well cleaned, free from scrap & wooden pieces carrying nails etc. Safety guard provide on the machines should be in proper position & well secured. Safety guard provide on the machines should be in proper position & well secured.

While working on a band saw it should be ensured that the guides are properly adjusted. 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. Turning tools should be held firmly. Use goggles while turning & sawing. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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. 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. 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.

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. Can be used for decorating the furniture as well as houses. It is also available in bigger sizes. 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. Natural Defects are the defects which are caused in the tree due to abnormality in the grouts. Defects are also caused during seasoning operation. Some defects are also there due to termites or insects. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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) 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. (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) 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 10- 20%. 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura.

Patiala- 140401 (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. 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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) Jack plane: Jack plane is 10”-14” long.

Heavy and is used for rough cutting. (c) Smoothing plane: Smoothing plane is used for finishing work. It is small in size generally 9” long. (d) Rebate plane: Rebate planes are used for preparing household goods are furniture plough plane is used for making grooves. (e) Moulding plane (f) Plough plane (g) 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. 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura.

Patiala- 140401 Objective: 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.

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

Mark other size (i.e. 30 mm or 40 mm) on the job piece and remove extra material. Mark two pieces each 150 mm in length with the help of pencil, try square and rip saw. Mark on the both job piece as per given dimensions with the help of pencil, try square and marking gauge. 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. Fit the job pieces in the shape of “T=- LAP JOINT” Safety Precautions 1.

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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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” Drawing: - See Diagrams Procedure:- 1. Taken a wooden piece slightly more than given dimension.

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

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. Mark other size (i.e. 30 mm or 40 mm) on the job piece and remove extra material. Mark two pieces each 150 mm in length with the help of pencil, try square and rip saw.

Mark on the both job piece as per given dimensions with the help of pencil, try square and marking gauge. 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. Fit the job pieces in the shape of “CROSS LAP JOINT” Safety Precautions 1. 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 Objectives: 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 Drawing: - See Diagrams Procedure: 1. Procure mortise and Tenon members of required dimension. Square the piece to the suitable dimension and mark their faces. 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. Now use a mortises gauge, mark the thickness of the Tenon. 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. In order to avoid tearing of mortises while chiseling. Layout an additional check cut at both Tenon and mortises members. Saw off the thin pieces of wood along the layout lines already marked, by using Tenon saw or rip saw.

Then trim off any unevenness with a sharp chisel. 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. 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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. 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. 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.

Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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. 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. 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 SAFETY PRECOUTION FOUNDRY SHOP 1. 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. Grasp the ladle firmly & be sure it is well balanced while transporting molten metal. Handel hot pieces with tong. Keep a clear space around the pouring area. Do not tough a casting immediately after removing from mould. Wear proper tools while working in the pouring area.

The shop should be properly lighted & ventilated to avoid accident. The moulding boxes should be properly lighted & ventilated to avoid bursting. Switch off the electric grinder after use & do not place it not places it on floor while in operation. If you see any accident happing you immediately inform the instructor. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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. 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.

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. 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. 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.

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

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Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 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. SMOOTHER AND CORNER SLICKS: they are also finishing flat and round surfaces round or square corners and edges. 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. 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. Bellow; it used to blow but the loose or unwanted sand from the surface and 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 tapped holes. MOULDING BOXES: The moulding boxes or flasks used in sand moulding are of two types; (a) Closed moulding boxes.

(b) 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.

Mechanical Engg Workshop Lab Manual Carpentry

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. Aluminium;brass;zinc etc. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura.

Patiala- 140401 TYPES OF PATTERNS 1. Solid or single piece pattern. Two-piece or split pattern. Multipiece pattern.

Match plate pattern. Gated pattern. Skeleton pattern.

Sweep pattern. Pattern with loose pieces. Cope and drag pattern. Follow board pattern. Segmental pattern. MOULDING PROCESSES: 1. MOULDING PROCESSES: a) Floor moulding.

B) bench moulding c) pit moulding d) machine moulding 2. ACCORDING TO THE MOULD MATERIALS i) Sand moulding a) Green sand moulding b) Dry sand moulding c) Core sand moulding d) Cement bonded sand moulding e) Shell moulding f) Skin dried sand moulding g) loam moulding ii) plaster moulding iii) Metallic moulding CASTING PROCESSES 1. Sand mould casting 2. Plaster mould casting 3.

Metallic mould casting a) gravity or permanent mould casting b) slush casting c) pressed casting. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 d) die casting 4. Centrifugal casting 5. Precision casting 6. CO2 mould casting 7.

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. Natural sand b.

Synthetic sand TYPES OF SAND USED IN MOULDES 1. Green sand 3. Facing sand 5. Parting sand 6.

Backing sand 7. Molasses sand COMPOSITION OF GREEN SAND 1. Silica sand 75% 2.

Coal dust 8% 3. Bentonite sand 12% 4. Water 5 to 6% PROPERTIES OF MOULDING SAND 1. Porosity and permeability 2. Refractoriness 3.

Adhesiveness 4. Cohesiveness 5. Chemical resistance 6.

Plasticity 7. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura. Patiala- 140401 MAIN CONSTITUENT OF MOULDING SAND The principal constituents of moulding sand are 1. Silica sand 2.

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. Organic binders 2.

In organic binders (ORGANIC) (INORGANIC) 1. Linseed oil 2. Certain binders 4.

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Resins, phenol formaldehydes 6. 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. Manufacturing Practice (ME-104) Page: / Chandigarh- Patiala National Highway, Teh.- Rajpura.

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Patiala- 140401 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. Half core box. Dump core box 3.

Split core box 4. Right and left core box 5. 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. Core blowing 2.

Core shooter.