Hammer heads are made of cast steel and, their ends are hardened and tempered. The striking face is made slightly convex. The weight of a hand hammer varies from about 0. It is used for finishing corners in shouldered work where the flatter would be inconvenient.
It is also used for drawing out the gorging job. Anvil An anvil is a most commonly tool used in forging shop which is shown in. The body of the anvil is made of mild steel with a tool steel face welded on the body, but the beak or horn used for bending curves is not steel faced.
The round hole in the anvil called pritchel hole is generally used for bending rods of small diameter, and as a die for hot punching operations. The square or hardie hole is used for holding square shanks of various fittings. Anvils in forging shop may vary up to about to kg and they should always stand with the top face about 0.
This height may be attained by resting the anvil on a wooden or cast iron base in the forging shop. Swage block Swage block generally used in forging shop is shown in figure. It is mainly used for heading, bending, squaring, sizing, and forming operations on forging jobs. It is 0. It may be used either flat or edgewise in its stand.
Drawing-down: Drawing is the process of stretching the stock while reducing its cross-section locally. Forging the tapered end of a cold is an example of drawing operation. Upsetting: It is a process of increasing the area of cross-section of a metal piece locally, with a corresponding reduction in length.
In this, only the portion to be upset is heated to forging temperature and the work is then struck at the end with a hammer. Hammering is done by the smith student himself, if the job is small, or by his helper, in case of big jobs, when heavy blows are required with a sledge hammer.
Fullering: Fullers are used for necking down a piece of work, the reduction often serving as the starting point for drawing. Fullers are made of high carbon steel in two parts, called the top and bottom fullers. The bottom tool fits in the hardie hole of the anvil. Fuller size denotes the width of the fuller edge. Flattering: Flatters are the tools that are made with a perfectly flat face of about 7. These are used for finishing flat surfaces. A flatter of small size is known as set-hammer and is used for finishing near corners and in confined spaces.
Swaging: Swages like fullers are also made of high carbon steel and are made in two parts called the top and swages. These are used to reduce and finish to round, square or hexagonal forms. For this, the swages are made with half grooves of dimensions to suit the work.
Bending: Bending of bars, flats, etc. Sharp bends as well as round bends may be made on the anvil, by choosing the appropriate place on it for the purpose.
Twisting: It is also one form of bending. Sometimes, it is done to increase the rigidity of the work piece. Small piece may be twisted by heating and clamping a pair of tongs on each end of the section to be twisted and applying a turning moment. Larger pieces may be clamped in a leg vice and twisted with a pair of tongs or a monkey wrench.
However, for uniform twist, it must be noted that the complete twisting operation must be performed in one heating. Cutting Hot and Cold Chisels : Chisels are used to cut metals, either in hot or cold state.
A hot chisel is used for cutting hot metal and its cutting edge is long and slender when compared to cold chisel. These chisels are made of tool steel, hardened and tempered. Again, based on the carbon content, it is called mild steel, medium carbon steel and high carbon steel. The heat treatment to be given to these steels and their applications are shown in table below. Carbon Hardening Tempering Applications. The following are the purposes of heat treatment: i. To remove internal stresses set-up during forging and cooling.
To normalize the internal structure of the metal. To improve machinability. To improve mechanical properties, strength and hardness. Hold the hot work downwards close to the ground, while transferring from the hearth to anvil, to minimize danger of burns; resulting from accidental collisions with others.
Use correct size and type of tongs to fit the work. These should hold the work securely to prevent its bouncing out of control from repeated hammer blows. Care should be exercised in the use of the hammer. The minimum force only should be used and the flat face should strike squarely on the work; as the edge of the hammer will produce heavy bruising on hot metal. Water face shield when hammering hot metal. Wear gloves when handling hot metal. Wear steel-toed shoes. Ensure that hammers are fitted with tight and wedged handles.
Sequence of operations: 1. Using the pick-up tongs; the rod is taken from the forge, and holding it with the half round tongs, the heated end is forged into a tapered pointed end. The length of the rod requires for S-hook is estimated and the excess portion is cut-off, using a cold chisel. One half of the rod towards the pointed end is heated in the forge to red hot condition and then bent into circular shape as shown.
The other end of the rod is then heated and forged into a tapered pointed end. The straight portion of the rod is finally heated and bent into circular shape as required. S- HOOK 7. Using the flatter, the S-hook made as above, is kept on the anvil and flattened so that, the shape of the hook is proper.
Result: The S-hook is thus made from the given round rod; by following the stages mentioned above. Precautions: 1. Hold the job carefully while heating and hammering 2. Job must be held parallel to the face of the anvil. Wear face shield when hammering the hot metal 5. Take the raw material from stock i. The required piece heated upto it gets the recrystalization temperature.
The part is taken out from the forge and blow with sledge hammer for obtaining the square shape on all edges. The hammering is done on the anvil. The above mentioned all steps are done, after the specimen bent in required shape. Check the dimensions after cooling the job by quenching process. Result: The square rod is thus made from the given round rod. The products produced are used in building construction, such as doors and windows, furniture manufacturing, patterns for moulding in foundries, etc.
Carpentry work mainly involves the joining together of wooden pieces and finishing the surfaces after shaping them. Hence, the term joining is also used commonly for carpentry. A student studying the fundamentals of wood working has to know about timber and other carpentry materials, wood working tools, carpentry operations and the method of making common types of joints. Materials Used in Carpentry: Basic materials used in carpentry shop are timber and plywood.
Auxiliary materials used are nails, screws, adhesives, paints, varnishes, etc. Timber: Timber is the name given to wood obtained from exogenous outward growing trees. In these trees, the growth is outward from the centre, by adding almost concentric layers of fresh wood every year known as annual rings. After the full growth, these trees are cut and sawed to convert into rectangular sections of various sizes for engineering purposes. Timber is available in market in various shapes and size.
The common shapes and sizes an: given below: 1. Log: This is the trunk of die tree which is tree from branches. Balk: This is the log after sawing roughly to square cross section. Deal: This is the log after sawing into rectangular cross section of width about mm and thickness up to mm. Plank: This is the timber piece having width more than mm and thickness 50 lo mm. Board: This is the timber piece below 50 mm in thickness and above mm in width, 6.
Batten: This is the timber piece below mm in width and thickness between 30 mm to 50 mm in thickness. Scantlings: These are timber pieces of various assorted and nonstandard sizesother than the types given above.
Classification of Wood The timber used for commercial purposes can he divided into two classes as soft wood and hard wood Soft wood A soft wood is light in weight and light colored. They may have distinct annual rings but the medullar rays radial lines are not visible and the color of the sap wood outer layers is not distinctive from the heart wood inner layers.
These woods cannot resist stresses developed across their fibers; hence, not suitable for wood working. Hard woods are nearly equally strong both along and across the fibers.
Hand wood is the material used for wood working Classification of timber According to the manner of growth of trees, timber can be classified as i Exogenous or out ward growing ii Endogenous or in ward growing i Exogenous or out ward growing In exogenous trees the growth take place from the centre by the addition of concentric layers of fresh wood every year, known as annual rings.
Different methods of seasoning 1. Air seasoning or Natural seasoning 2. Water seasoning 3. Electrical seasoning 4. Kiln seasoning Ply wood Thick sheet formed by pasting veneers of wood is called ply. Three or more plys joined by glues is called plywood. The grains of adjacent layers are kept at right angle to each other in order to get better strengthening both directions the outer layer are called facing plys and good hard wood veneers are used for this inner ones are called core plys and low quality wood is used for this the ply wood is made by either cold pressing or hot pressing.
Tools for wood working The principle hand tools used in a carpentry workshop can be classified into i Marking and measuring tool ii Cutting tool iii Planning tool iv Boring tool v Striking tool vi Holding tool Marking and measuring tool a Rules Rules are used for measuring dimensions. For measuring and setting out dimensions various types of rules are used in carpentry shop. Steel Rule- Stainless Steel Rule of length 30cm and 60cm.
Flexible Measuring Rule- for measuring large dimensions as well as curved or angular surface dimensions. It mainly consists of a wooden stem sliding inside a wooden stock.
The stem carries a steel point for marking lines. The stock position on the stem can be varied and fixed rigidly by tightening the thumb screw. Mortise Gauge c Try square Try square consists of rectangular steel blade fixed rigidly to cast iron stock.
The length of blade varies from mm to mm. Marking Knife or Scriber Marking Knives are used to convert the pencil lines drawn on the wooden surface into deep scratch lines on the surface. They are made of steel with a sharp point at one end and flat blade at the other end. Marking Knife Fig. Try Square Bevel Square: it is also called sliding level. VI Holding tools a Work Bench This is a table of having size and raised construction made of hard wood. The size ranges from 80 cm in length and about 90cm in width.
Two Fig. Bevel Square or four carpenters can work at a time on the work bench. Carpenters Bench Vice It consists of jaw fixed on the table side and movable jaw kept in position by means of screw and handle. The body of vice is made of cast iron or steel. The jaws are lined with hard wood which can be removed when it is damaged.
Work Bench with Bench Hook The screw moves inside the fixed half nut which can be engaged or disengaged by operating the lever.
This is made up of a bar of steel. The work is clamped between jaws by rotating the screw using the handle. It is used for clamping glued pieces or holding the work piece of larger size together for various operations.
These clamps are available is sizes varying from 70 mm to mm. Carpenters Bench Vice Fig. Bar or T-Cramp Fig. C- Clamp Bar or T-cramp: it consists of a steel bar fitted with a threaded spindle and an adjustable shoe. It is used for holding the glued pieces tightly or holding firmly two or more unglued pieces for fitting dowels or doing other operations on them in assembled position.
II Cutting tools a Saws Saw is a cutting tool which has teeth on one edge and cutting is affected by reciprocating motion of the edge relative to the work piece. Cutting occurs during the forward motion; such a saw is called push type saw, the cutting occurs during the backward motion.
Hand Saw- This saw is used for short straight cuts. It has a blade of cm length 6- 10cm width. The number of teeth per cm length ranges from Tenon Saw Back Saw - It has a parallel blade of cm length and cm width. Firmer Chisels- they are most common and general purpose chisel used by a carpenter.
They have flat blade of mm width and mm length. Dove Tail Chisel beveled edge firmer chisel - These chisels are used for fine and delicate works as well as for cutting corners. Mortise chisel — These chisels are used for heavy and deep cut to remove large quantity of wood. These chisels have width of about 15mm but the blade thickness may range from 6- 15mm. Saws Fig.
Parts of a Chisel Fig. Cross-cut Saw Fig. Rip Saw Fig. Parts of Saw Fig. The main part of a wooden jack plane is a wooden block called sole, in which steel blade having knife edge is fixed at an angle with the help of wooden edge. The body of a metal jack plane is made from a grey iron casting with the side and sole machined and ground to better finish.
Gimlet Drill Fig. Plane b Carpenters brace: it is used for rotating auger bits, twist drills, etc. In some designs, braces are made with ratchet device. During drilling, the lead screw of the bit guides into the wood, necessitating only moderate pressure on the brace. The helical flutes on the surface carry the chips to the outer surface. A straight shank drill is used with this tool. It is small, light in weight and may be conveniently used than the brace.
The drill bit is clamped in the chuck at its end and is rotated by a handle attached to gear and pinion arrangement. It is used for drilling large diameter holes with the hand pressure. Striking Tools a Mallet This is wooden headed hammer of round or rectangular cross section. The striking face is made flat. Mallet is used for striking the cutting tools and has wooden handle. The flat face of the head is used toFig. Mallet drive nails and claw portion for extracting nails out of the wood. Pincer Fig.
Claw Hammer c Pincer: it is made of two forged steel arms with a hinged joint and is used for pulling-out small nails from wood. The inner faces of the pincer jaws are bevelled and the outer faces are plain. The end of one arm has a ball and the other has a claw. The bevelled jaws and the claw are used for pulling out small nails, pins and screws from the wood. The length of a screw driver is determined by the length of the blade.
As the length of the blade increases, the width and thickness of the tip also increase. Screw Driver Wood rasp files: it is a finishing tool used to make the wood surface smooth, remove sharp edges, and finish fillets and other interior surfaces. Sharp cutting teeth are provided on its surface for the purpose. This file is exclusively used in wood work. Steel rule 2. Try square 3. Marking guage 4. Rip saw 5. Tenon saw 6. Mortise chisel 7. Mallet 8. Jack plane 9.
Planning 2. Marking 3. Sawing 4. Chiseling 5. The wooden pieces are made into two halves and are checked for dimensions. One side of pieces is planned with jack plane and for strraightness.
An adajacent side is planned and checked for squareness with a try square. Marking guage is set and lines are marked at mm to make the thickness and width according to given figure. The excess material is planned to correct size. Using tenon saw, the portions to be removed are cut in both the pieces 7. The excess material in X is chiseled with mortise chisel. The excess material in Y in chiseled to suit X 9.
The end of both the pieces is chiseled to exact lengths. Wood should be free from moisture 2. Marking is done with out parallax error 3. Care shoukd be taken while chiseling 4. Matching of X and Y pieces should be tight. One side of pieces is planned with jack planeand for strraightness.
Marking guage is set and lines are marked at mm to make the thickness and width according to given figure 5. Reaper should be free from moisture 2. Matching of x and y pieces should be tight. The operations required for the same are usually carried out on a work bench, hence the term bench work is also added with the name fitting.
The bench work and fitting plays an important role in engineering. Although in today's industries most of the work is done by automatic machines which produces the jobs with good accuracy but still it job requires some hand operations called fitting operations. Work Bench A fitting process can be done at various places, but most of the important operations of fitting are generally carried out on a table called work bench.
The work bench is a strong, heavy and rigid table made up of hard wood. The size of the work bench required is about to cm length, nearly 90 cm width and approximately 76 to 84 cm height. It consists of a cast Iron body and cast iron jaws. Two jaw plates are fitted on both the jaws.
The holding surface of the jaw plates is knurled in order to increase the gipping. Jaw plates are made up of carbon steel and are wear resistant.
One jaw is fixed to the body and the second slides on a square threaded screw with the help of a handle. The jaws are opened upto required length; job is placed in the two jaws and is fully tightened with the help of handle. The screw of the clamp applies the holding pressure. When the handle is rotated there is movement in the screw. These are marked in inches or millimetres.
All the faces are machined true. The edges of steel rule should be protected from rough handling. Calipers These are generally used to measure the inside or outside diameters.
Different types are: i. Outside Caliper: It is used to measure the outside dimensions. Inside Caliper: It is used to measure the inside dimensions. Spring Caliper: Spring is provided to apply the pressure and lock nut is provided to lock any desired position.
Hermaphrodite, Jenny or Oddleg Caliper: One leg is bent at the tip inwardly and the other has a straight pointed end. It is used to scribe lines parallel to the straight edges. Calipers 3. Vernier Caliper: It is used for measuring the outer dimensions of round, flat, square components and also the inner size of the holes and bore.
A narrow blade is used to measure the depth of bar slots etc. The reading accuracy in metric system is 0. It is made of stainless steel.
Surface Plate It is used for testing the flatness, trueness of the surfaces. It is made up of cast iron or graphite. Its upper face is planed to form a very smooth surface.
It is also used in scribing work. While not in use, it should be covered with a wooden cover. Angle Plate It is made up of cast iron in different sizes; it has two planed surfaces at right angles to each other and has various slots in each surface to hold the work by means of bolts and clamps.
Never do hammering on the angle plate to fasten lighten the nuts and bolts. Scriber and Surface Gauge It consists of a cast iron bass on the center of which a steel rod is fixed vertically. Scriber is made up of high carbon steel and is hardened from the front edge. It is used for locating the centres of round bars or for marking of the lines.
Scriber and Surface Gauge 4. Punches Punches are used for marking purposes. Dot punches are used for marking dotted line and centre punch is used to mark the centre of hole before drilling. Punches are made up of high carbon steel or high speed steels. One end is sharpened.
Hammering is done on the second end while working. For dot punch, angle of the punching end is 60 degree while in centre punch; angle of punching end is 90 degree. Try Square It is used for checking squareness of two surfaces. It consists of a blade made up of steel, which is attached to a base at 90 degree. The base is made up of cast iron or steel. It is also used to mark the right angles and measuring straightness of surfaces.
Never use try square as a hammer. Vernier Height gauge: A Vernier height gauge consists of a heavy base, a graduated beam, a sliding head with Vernier sliding jaws holding the scriber and a fine adjustment clamp. It is similar to large Vernier calipers in construction, except that it consists of a heavy base which allows the gauge to stand upright instead of a fixed jaw in a Vernier.
The movable jaw of Vernier height gauge consists of a projection or extension which is levelled to sharp edge for scribing lines at any required height. The procedure Fig. The surface to be marked is coated with the paste of chalk or red slide C-Scriber clamp screw D — Scriber E lead and allowed to dry. Then the work is held In a holding device depending upon shape and size.
If it is flat, use surface plate, if it is round use V block and clamp, else use angle plate etc. Lines in horizontal direction are scribed by means of a surface gauge. Lines at right angles can be drawn by turning the work through 90 degree and then using the scriber. If true surface is available, try square can also be used. The centre on the end of a round bar can be located by using an odd leg caliper, surface gauge etc.
The circles and arcs on a flat surface are marked by means of a divider. After the scribing work is over, indentations on the surface are made using dot punch and hammer.
Hacksaw Hacksaw is used for cutting of rods, bars, pipes, flats etc. It consists of a frame, which is made from mild steel. The blade is placed inside the frame and is tightened with the help of a flange nut.
The blade is made up of high carbon steel or high speed Fig. Hand Hacksaws steel. The teeth of the blades are generally forward cut so in the case, pressure is applied in the forward direction only.
Depending upon the direction of cut, blades are classified as: o Forward cut o Backward cut. Files Files are multi points cutting tools. It is used to remove the material by rubbing it on the metals.
Files are available in a number of sizes, shapes and degree of coarseness. Classification of files i. When the material removal is more, these files are used. These files have bigger cut but the surface produced Is rough. Dead smooth and smooth files have smaller teeth and used for finishing work. Second cut file has degree of finish in between bastard and smooth file. In single cut files the teeth are cut in parallel rows at an angle of 60 degree to the face.
Another row of teeth is added in opposite direction in case of double cut files. Material removal is more in case of double cut files. The various shapes of cross-section available are hand file, flat file, triangular, round; square, half round, knife-edge, pillar, needle and mill file. Flat file: This file has parallel edges for about two-thirds of the length and then it tapers in width and thickness. The faces are double cut while the edges are single cut.
Hand file: for a hand file the width is constant throughout, but the thickness tapers as given in flat file. Both faces are double cut and one edge is single cut. The remaining edge is kept uncut in order to use for filing a right-angled corner on one side only. Square file: It has a square cross-section. It is parallel for two-thirds of its length and then tapers towards the tip. It is double cut on all sides.
It is used for filing square corners and slots. Triangular file: It has width either parallel throughout or upto middle and then tapered towards the tip. Its section is triangular equilateral and the three faces are double cut and the edges single cut.
It is used for filing square shoulders or comers and for sharpening wood working saws. Round file: It has round cross-section. It carries single cut teeth all round its surface. It is normally made tapered towards the tip and is frequently known as rat-tail file. Parallel round files having same diameter throughout the length are also available. The round files are used for opening out holes, producing round comers, round-ended slots etc.
Half-round file: Its cross-section is not a true half circle but is only about one-third of a circle. The width of the file is either parallel throughout or upto middle and then tapered towards the tip.
The flat side of this file is always a double cut and curved side has single cut. It is used for filing curved surfaces. Knife edge file: It has a width tapered like a knife blade and it is also tapered towards the tip and thickness. It carries double cut teeth on the two broad faces and single cut teeth on the edge. It is used for finishing sharp corners of grooves and slots h. Diamond file: Its cross-section is like a diamond. It is used for special work. Needle file: These are thin small files having a parallel tang and a thin, narrow and pointed blade made in different shapes of its cross-section to suit the particular need of the work.
These are available in sizes from mm to mm of various shapes and cuts. These files are used for filing very thin and delicate work. Methods of filing The following are the two commonly used methods of filing: 1. Cross-filing 2. Draw filing. Cross - filing. Refer Fig. This method is used for efficient removal of maximum amount of metal in the shortest possible time. It may be noted that the file must remain horizontal throughout the stroke long, slow and steady with pressure only applied on the forward motion.
Here, the file is gripped as close to the work as possible between two hands. In this filing method, a fine cut file with a flat face should be used. When particles of metal clog the teeth the file is said to the pinned, a condition that causes scratching of the surface of the work.
Files, therefore, require cleaning by means of a file card or by dislodging the material between the teeth by means of a piece of soft iron, copper, brass, tin plate and so on, sharpened at the end. Hardened steel should never be used Fig. Odd leg caliper 3. Dot punch 9. Introduction to workshop practice, safety, care and precaution in workshop. Module 2. Bench work tools and processes Lesson 2. The bench work tools and its uses Lesson 3. The bench work tools, its uses and processes.
Module 3. Smithy and forgoing tools and operation Lesson 4. Smithy and forging tools and equipment Lesson 5. Smithy and forging operation. Module 4. Heat treatment process Lesson 6. Heat treatment processes: Hardening, tempering, annealing and normalizing Lesson 7. Metal Cutting. Module 5. Welding Lesson 8. Electric arc welding Lesson 9. Gas Welding. Module 6. Workshop Practice Series No. Welding by oxy-acetylene or electric arc is a skill in increasing demand and one of which the basics can be learned without great difficulty.
In this book, W. Vause, who spent many years as a welder and several as Welding Instructor …. Everyone needs some form of measurement during workshop production or making any part. How to use measuring equipment and how to mark out work is not always simple. Essential skills are required to use the measuring instrument and its …. The lathe and a drilling machine can be used for milling work operation as basic machines. Lath is a universal machine can be adapted for almost any function its most valuable use is for milling work is practical ….
Foundrywork for the amateur workshop practice series No. Terry Aspin.
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