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== INTROUDCTION TO FITTING == In the progressive age a kind of revolution has taken place in industries all over the world. In order to meet our day today material, a number of new machines have becomes on integral part of our life. How difficult our life would become without the machines. We have used a number of machine daily for eg. Scooter, by cycle, sewing machine, television and aero plane etc. All this things are manufactured in different workshop in different countries. This workshops and factories are very large in size according to over needs and their utility this may be small medium or large scale industries but basic of the production in small industries and the technician who work their every motion needs technicians for the production and repair of various machines. Fitter is one of the important trade in which a training is given to the technician who fit something under this trade. •We have three categories 1)Machine fitter 2)Bench fitter 3)Pipe fitter

1)Machine fitter A technician who fit different parts and assemble or produce a machine comes under this categories this part might have been made by a technician of some other trade or by the fitter himself.

2)Bench fitter A technician who make or repair a part of a machines by using different kind of hand tools who can fit different types of jobs.

3)Pipe fitter A pipe fitter is who performs all kinds of pipe fitting job, this may be piped uses for tap in house, pipe used in cold storage or pipe used in boiler.

'LIMITS, FITS AND TOLEARANCE ALLOWANCE'''

The two machine part are fitted in a certain limit the shafts and the hole are allowed to fit between certain dimension for any part there are two size maximum size and other one in minimum size upper limit reading may be 25 to 0.5mm and lower limit reading may be 24.95mm. B.S.T System: The difference between high limit and low limit may be fixed in two ways and that is called unilateral system and bilateral.

Unilateral system: If the tolerance is fixed on any size of the basic dimension and this system is called unilateral system.

Bilateral system: The tolerance extends or fixed on both direction but not always it should be equal amount from the design size. Therefore the hole or shaft is bilateral. E.g. let the basis size is 25mm and the tolerance is 0.5mm Unilateral system = +10.05 mm        -    - 0.00mm

Bilateral system = +0.03 mm        -  -0.02 mm

Tolerance: The word tolerance indicates that the operator is not able to produce interchangeable part to the definite accurate size but the work may be completed with certain range of error their for the tolerance is defined as the margin for error either workmanship or in appliances the tolerance differ between high limit and low limit. Advantages and tolerance 1)	With tolerance, job is completed rapidly. 2)	It helps in mass production. 3)	It saves time. 4)	It saves material.

Basic limit and its advantages: The size of the shaft of fixed and it should not be changed so the tolerance should be given to the hole only and it is called shaft basis.

Allowance: Allowance is defined as the deft in size of two maching parts which is necessary to obtain desired fit therefore allowance is differs between upper limit and lower limit. Fit: Fit is a joint classified according to the nature appile association male and female future by which the two belts when they take the sources are male and female that is called fit. Definition: Some interchangeable part shall to be fitted and also replaced without additional fitting or other treatment so this part must be produced in small way that they fit together correctly and accurately the fit should the relation between the two matching components of male and female feature that is shaft and the hole in 1st system, it is also the same as well or a new all system but instead of having limit in inches unit, the limit are grouped in various grades showing in inches and in metric units. Different types of fits: There are different types of fits 1) B.AS.I 2) Newall  3) I.S.I system 1)Newall system: According to newall system the hole is finished accurately and the size of the shaft is finished to describe  fit. The limit for the matching componed is given in a newall std table the types of fits are 1) Fore fit 2) Drive fit  3) Push fit 4) Running fit  5) Shunk fit 2)B.S.I. System: According to B.S.I. System the limit is fixed in two ways. That is unilateral and bilateral system. The tolerance is denoted by letters. 3)I.S.I. System: The I.S.I system is also the same as newall system but instead of showing the limit in inches it is grouped in various grades showing the value of limit in metre unit. Lower limit: The different between min limit and the normal sizes. Maximum clearance: The different between the max size of hole and min size of the shaft. Maximum clearance: The different between the min size of hole and max size of the shaft. Maximum interference : The different between max size of the shaft and the min size of the hole. Minimum interference: The different between the min size of shaft and the max size of the hole. Importance of grade fits: The accuracy of the machine depends upon the nature of types of parts. The parts are manufactured with the specific limit having various types of fit for the machine. The part may be given better for the machine e.g. A boll bearing in inserted on a shaft giving light blows and this is called interference fit. A gear is inserted on the shaft by push fit and this is called transition fit and a shaft is moving in a bearing and this is essential in all machine to the grade of fit is more important to keep the machine in perfect condition by using various grade of fit. The machine can be also used for longer period.

Definition and classification of types of fit in BIS: 1)Interference fit: In this fit diameter of the shaft is bigger than diameter of the hole. In this fit the hole creates same interference in fitting of the shaft it becomes steady in the hold by this both the parts are strongly joined.e.g. A secure is forced into the hub of meter etc. The other fits which come under the fit are 1) force fit 2) shunkege fit 3) During fit 4) Press fit 5) Tight fit. 2) Transition fit: The fit is supported to be intermediates between the transition fit and clearance fit. This fit is neither tight or loose for this fit. The dia of the shaft and the hole are kept in such a way that they are sliding and moving together by striking. In this fit neither there is any cause of clearance or any interference between the level of the hole and the shaft e.g. Boll enter into the hole and the crank of the rals 2) the nut sliding over the boll etc. 3) Clearance fit: This fit the dia of the shaft is less than the dia of the hole. There is clearance in the surface of the shaft and the hold so that the shaft can move or remove freely and easily in the hole thus for the difference of jow different clearance are allowed which comes max and mix it is classified according to the clearance expressed by letter x,y,z the grade x is suitable for the free loose rumening for high speed and z for precision running eg. This fit is used in a bush bearing the foll fits come under this fit. 1) Running fit  2) Sliding fit

Definition of various fit (Type of fit) 1)Force fit: The shafts are finished according to the table of neuroll or ISI system it is forced into the matching hole by mechanical pressure and the hold expends to assemble the parts. This type of fit is called as force fit e.g. a slives is forced into the hub.

2)Driving fit: A shaft and the hold are finished to a desired tolerance as such that the shaft is drivan into the hole by a suitable hammer blower this type of fit is called as driving fit e.g. Boll bearing etc.

3)Shrink fit: Metal has tendency to expand or increase in val. When heated due to sudden cooling. i.e. on shrinikage will grip the part, closely this type of the fit is called as shrinkage fit e.g. A cast iron on a wooden wheel.

4)Push fit: In this fit the parts are heated by the pressure of hand. This type of fit is called as push fit in this fit the male part is free moving without any obstruction eg. A shaft is freely moving and resolving in a bush bearing.

5)Interchangeable and its advantage: The fit is the capacity of the parts to replace the parts but or order in a short time without any additional fitting or treatment interchangeable parts are manufactured in large quantities setting tools in a fixed position or using various machines or attachment for interchangeable there are certain advantages.

6)Advantages: Spare parts are available in cheap rate due to mass production easy to setup the tools without extra work or treatment. The machine is same ideal which make the heavy class to bring the production for cheap. Definition: 1)Normal size: The fixed for the job in normal size or design size or bases size. Actual size the size which the finished by the operator is called the actual size. 2)Copper limit. Difference between the max limit and the normal limit.

BEARINGItalic text Bearing are largely used for supporting the moving part and sliding part of machine generally shaft are supported on bearing and they are either required to slide or rotate inside the bearing. Bearing are made in wide range having various uses and they are fitted according to load and the speed of the shaft there is sufficient clearance bit shaft and the bearings. It is used to reduce friction bearing are classified into two types frictional and anti frictional. Definition: Bearing are supporting devices which are having various duty these bearing are mostly made of various shape and designs when ever the shaft is in action by power of transformation it is required to reduce the friction of the shaft the base permit the shaft to move on or reduce with out friction. Bearing are generally made of soft material and hard material frictional bearing are made of brass, copper, gun metal bronze etc where anti frictional bearing they are of hard metal such as alloy, steel chromium etc. Advantages of bearing and uses. 1)Supports shaft which it is running 2)Guide the shaft 3)Help in smooth running of shaft 4)Help in increase of load 5)Reduce friction 6)Increase speed. 7)They are interchangeable.

Types of bearings: There are various types of bearings which are used to support the shaft, to guide the shaft and to reduce the friction. These bearing are classified in two group 1) Plan or frictional bearing 2) Anti frictional bearing. Frictional bearing are available in solid as well as split form where an anti frictional bearings are available in various design and mostly circular in sution and they are boll bearings roller bearing, trust etc. Frictional bearing: In frictional bearing there are no roller element such as balls or rollers such types of bearing are available e.g. bust

Bush bearings; It is hallow and round in shape. Its shape can be made round or rectangle as desired inside measurement is made according to dia of the shaft it is also called solid bearings made of brass, copper etc. these bearings are used for shaft having more R.P.M.

Journal bearings; Journal bearing is frictional bearing which is splited in two half’s. This bearings is made of soft materials such as brass etc. It is designed and molted into slaves according to required size and has a loller an either side to the fix on housing. They are generally used to carry heavy loods where the dia of shaft is bigger. These bearings are also used where the shaft runs at high speed.

Ball bearings; Ball bearings are used for light and heavy load either is slow or heavy speed it depends upon the size, types of walls and its capacity single raw boll bearings are used for high speed shaft caring high lead and medium lead. Thus row boll bearings are used in high speed caring heavy lead. They are classified according to dia of bore the outer dia and the tyers of balls fixed in single or double row. Ball bearing are made of alloy steel Nickel chorminium steel etc. for this bearing there are two different size in dia of rings are called as ralles, Bare of the innder rale is accurately finished to the size of the shaft having a centive groove around the outer surface the bolls groves altmdale the balls. The bolls roll item sell in briks the outer rate is fixed into a housing and clamped tightly the inner rale rotates since it is fixed with the shaft thenis only one pant for this bearing called cage it is made of non ferrous sheet metal fixed on either side of the rales to told bearing in the proper tarakes.

Methods of fixing boll bearing on shaft 1)By using the housing. 2)Inserting the outer role in the groove. 3)By fixing clamp on outer surface. 4)By using taper bush.

Roller bearing; There are rollers instead boll the rollers are used for making friction between rings to result the crusting effect of heavy load. Rollers are made of chromium steel etc and they are hardened polished rollers are placed is serious together between the two steel rings and they are retained in equal spare position made by gun metal cage compressing the two steel rings seam together by steel. Pins by revitted. When the roller bearing is inserted into a shaft the inner role is fitted on the shaft by driving fit and it rotates with the shaft. The outer role is secured firmly in the housing and it does not rotate but rollers between the two role rotater these bearing are mostly used for high speed combining with heavy lead they are classified according to dia of bore, outer dia and with of the bearing.

Foot step bearing; Foot step bearing is anti frictional bearing which is used for separating the pressure when it is vertically up ward that is to the shaft axis. In foot step bearing the shaft end is resting with the bearing.

Thrust bearing; this type of bearing is largely used when pressure is to the axis of the shaft having the end thrust or axis thrust. While metal bearing; this bearing is constructible are to suitable design for the machine. It is soft in nature barbit metal bearing is also similar to white metal bearings.

These bearings are used on shaft moving at high speed and with heavy load.

Various type of bearing metal and their uses bearings are available of various metals. 1)Brass bearing; It is very soft metal used to protect shaft while is running at show speed carrying high load. 2)Bronze bearing; It is a good metal for bearing to carry heavy load at medium speed. 3)Phosphorous Bronze bearing; this property of this metal is it hard and fit for manufacturing whone wheely gears and bearings these bearing are used run shaft freely. 4)Gun metal bearings; It is used to run shaft which carry heavy load at medium speed. 5)White metal bearing; this metal is shaft and helps shaft to run freely without heat, this metal and runs leaving shaft undamaged. 6)Babbit metal bearing; Babbit metals is shaft in nature this type of bearing is used where shaft is moving at high speed with heavy load.

Advantages of anti frictional bearing over plain bearings. 1)It help for smooth running of shaft is less power is required. 2)Fit for high and slow as well as heavy and light load. 3)No wear and tear 4)Easy to set up 5)Available readily 6)No damage to shaft

Definition of housing and its construction. A compound which hold the outer surface of bearing is called housing. It is made of two values the bottom portion lies on the ground where the foundation both are used to fix. It has slot holes on both end for adj. Breath of bearing color there is reservoir in the housing to store oil for the ring lubrication system. Plain bearing are also available turns studs are fixed on each side of the bottom housing hold the top part. Housing is generally constructed of cost iron of regd size and required shape.

Re-fitting process of white metal and babbit metal the grooves and the inner surface of the bearing should be clean and trined and better gerping of metal.

The two half bearing may be clamped tightening to avaied leakage, liners may be placed if required core may be insered in the correct position. The side of core should have slide tapper and lesser then the shaft size providing allowance melting point may be heated putting sufficient gtey of while metal and babbit metal, the body of bearing is ground and the connoted part should be heated to wash away the moisture.

SAFETY

ACCIDENT An accident is an unplanned and non controlled event in which the action or reaction of an object, substance or person results in personal injury or probability there of.

CAUSES OF WORKSHOP ACCIDENTS. 1)Human causes; carelessness of over confidence cause accidents. 2)Hand Tools; suitable tools must always be selected for the given particular work. Accidents may occur if faulty or improper tools are used. 3)Working conditions; slipper floor, poor ventilation, poor lighting and inadequate space are potential causes of accidents. 4)Machines; unguarded machinery, poor maintenance, improper adjustments etc can cause accidents. 5)Materials; storage of inflammable and pointed tools of jobs can also accidents. 6)Person himself; An improper or uncomfortable dress as well as an improper position or posture can cause accident at work place.

SAFETY
Bold text A good craftsman is one who is safety conscious. He known and puts into practice safe and accepted procedures, learning to work. Safety is as important as learning the trade itself. Safety is an action which organizes and controls all our acts in such a manner that we don’t get involved, expose ourselves or others in an accident. Many accidents happen because people don’t behave sensibly in the workshop.

GENERAL SAFETY PRECAUTIONS. •Learn safe way of doing the job before you actually start. •Think of safety of act safety at all times. •Follow all the safety rules and regulations they are meant to protect you. •Put on proper and protective clothing. •Don’t indulge in horseplay. •Concentrate on the work and avoid unnecessary talking. •Handle only the equipment you have been authorized to work on. •Check up and inspect the tools for safe working from time to time. •Don’t attempt to oil, clean, adjust or repair any machine when its running. •Don’t try to stop a machine with your hands or body.

PERSONAL SAFETY 1)Wear a close fitting and comfortable dress. Never wear a loose shirt. 2)Never enter the shop without shoes. 3)Don’t wear rings, watches, etc that could get caught in the moving machinery. 4)Wear goggles whenever there is danger of flying matter.

House Keeping Good house - Keeping means safe strange of tools, components parts and all the items needed in the workshop. Important general rule for good house keeping are 1)Shop floor should be kept clean of grease oil or any other liquid, which may marks the floor dirty and slippery. 2)Gangways should be kept clean of everything. 3)Tools etc should not be left around on the table on the bed of the machine. 4)Tools should be kept away in proper place when not required. 5)Scrap should be thrown only in the scrap boxes.

FIRE AND FIRE ACCIDENTS. Fire is a rapid oxidation process in which heat and light are produced three substance i.e. combustible material, heat and oxygen are essential for spread of fire. By excluding any one of the three, the fire can be avoid or extinguished when fire causes an accident it is called fire accident.

TYPES OF FIRES. 1)Class A; Fires in ordinary combustible materials such as wood, paper, textiles and rubbish. 2)Class B; Fire in flammable liquids such as gasoline, solvents, oil, grease, paints, varnish and lac quers. 3)Class C; Fire on electrical equipment such as motors, generators and suitable panels. 4)Class D; Class D is the classification of fires involving combustible metals like magnesium potassium, powered aluminium, zinc sodium, litanium and other.

TYPES OF EXTINGUISHERS. 1)On class A: To extinguish such fire, the quenching or cooling effect of water or solutions containing large portions of water are required. 2)On class B; Here or blanketing or smothering effect is essential to put out the fire carbon di oxide, dry chemicals, vaporizing liquids. 3)On class C; Because of an electric hazard, a non conductive extinguishing agent is required such as carbon di oxide, dry, chemicals, vaporizing liquids. 4)On class D; This class of fire required special fire tactics and extinguishing agents.

FIRST AID It is the immediate and temporary care (pending arrival of doctor) given to a person who has met with an accident. It includes mental help to the victim as well as treatment of the injury. 1)Use proper first aid for the injury. 2)Ask someone to call a doctor and ambulance, if required. 3)Don’t leave the victim unless he is an danger of further injury. 4)Don’t leave the victim alone. 5)Reasure the victim that he will be all right because a good mental attitude is necessary in case if an accident.

FIRST AID.

It is immediate treatment given to a injured person before arrival of doctor or before taking him to the hospital. The person of first aid is given to a injured person so that he may recover of his life and to prevent further injuries. Accident can be happen in the workshop, laboratories, school, on road and so on the principle of first aid is quick service, rigid action, do not let the person to see him own injuries, and to remove the person from source of damage. The qualities of the first aid are lonfiadeness, quietly, system at, colly good command, reason full and to be a good listener.

Types of accident and treatment. While working in the engineering workshop different types of accidents can be cause such as. 1)Cuts Treatment 1)Stop bleeding 2)Observation 3)Remove foreign bodies. 4)Wash the wound with the detol or potassium permanganate. 5)Press the wound by using bandage.

2)Accident of fracture Treatment 1)See the person whether conscious or unconscious 2)Inured part should be immobilized. 3)If there is any cut immediately bleeding should be stop. 4)Give fresh air to the patient. 5)If available give him cold water and make comfortable.

3)Accident of burn Treatment 1)When the patient have been injuries around touching to the patient body and see that immediately apply to the patient olive oil, ink or burnol if possible. 2)Do not try to brack his blisters if there are any. 3)Make the patient comfortable. 4)Give fresh air. 5)If possible give the patient cold water

course of Treatment 1)Observe the patient if he is conscious our unconscious if he is unconscious give him artificial respiration by following methods such as. 2)Pressing the chest and relissing it. 3)Mouth to month artificial respiration. 4)When patient is conscious allow him fresh air, cold water try to loosen the cloth so that the patient will be comfortable.

SINE BAR
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For marking and in ensuring angle which are known the vernier beuel protector can be used up to an accuracy of 5mm but with the help of sin bar the unknown angle can be found out by using proper formula.

Various jobs can be measured and marked upto an accuracy of 5th but with sin bar measurement of jobs can be measured with degree and minute sin bar consist of a simple square or rectangle bar made of steel which is done to mark if highly place and smooth two rollers are fixed on both ends the upper and lower surface of sine bar are completely parallel to each other and in same way the centre to centre is the limit of that sin bar. This sine bar are normally available in various size 5’, 10’ and 20’ in inches and 150, 200, 300mm and Bigger size.

On basic of accuracy they are divided into 2 classes ‘A’ and ‘B’ accuracy of ‘A’ class is 0.0000 while ‘B’ class accuracy is 0.002. Sin bar work on principle of trigonometric ratio, therefore Sin B = perpendicular / hypotenuse i.e. Sin B = adjacent side -                 Hypotenuse.

METHOD OF TESTING AND SETTING SINE BAR For taking measurement with sin bar following instrument are necessary 1)	Surface plate 2)	Slip gauges or gauges block 3)	Sin bar 4)	Dial test indicators

The job which is to be measured should be placed on sin bar in which height one (4, 1) height two (42) should be raised with the help of stop gauge block. Now gauge are attached below rolar of sine bar. In this method job is measured these gauge block are fixed and placed on surface plate in such away that upper surface of job becomes parallel to surface plate, dial test indicator is used to check parallelism of surface gauge blocks. The total reading can be read is equal to perpendicular and sine bar measurement is hypotenuse of sin bar the measurement of sine bar is known by using sine tables in degree and in radium minutes.

PROBLEM ON SIN BAR AND SLIP GAUGE. 1)	Find height of slip gauge for an angle of 25 using sine bar of 200mm large Sine Q = A        C Q = 25

a = c

= 200 x 0.4226 =84.52 mm The height of slip gauge required is 84.52 mm.

2)	Calculate the angle for the tapper component the height of slip gauge is 84.52 and the length of sine bar use is 200mm.

Sine   = A          C    = 84.52 -       200 Sin Ø = 0.4226

Sin Ø = 25

3)	What will be angle of work piece. It the slip gauge height is 17.36mm and the size bars is use is 100mm.

Sine Ø  =  A            C    = 17.36 -      100 Sin Ø = Ø 17.36 Sin Ø = 10 The angle for the height of 17.36 is 10

JIGS AND FIXTURE
Bold text Jigs A Jigs is a special device which holds, supports locate and also guides the cutting tools during operation.

Jigs are used for drilling, reaming, tapping etc. these are of the following types according to there friction. 1)Plate jig 2)Angle jig 3)Channel jig 4)Box jig 5)Diameter jig 6)Ring jig 7)Ring jig 8)Jig bushing

1)Plate Jig; For boring in job made of plate jig is used. This jig is made of plate and its shape is axe to the job this jig guides the cutting tool. 2)Angle Jig; It is in shape of angle plate. This jig is used for drilling of cone pully etc. 3)Channel jig; This jip is made of channel section ordinary busing and means of fastening etc are used only rectangular jobs are held drilled. 4)Box jig; the shape of the jig is like a box job is closed in this box and it strikes to its plate. 5)Diameter jig; This type of jig is used for drilling in cylindrical jobs. 6)Ring jig; the type of jig is used for drilling in cylindrical frange or pieps.

Ideal principal for making jigs. 1)Cast of job made by jig should not be more than cast of job made by other loads in other words. If the cost of making jig is high it is better to use ordinary tools. 2)While making jig all the relevant information about job should be gathered. 3)Even a little mistake committed at time of making a jig can prove costly. 4)The design of jig should be strong to hold job and job should not be twisted. 5)The metal of jig should be light and should have adequate strength also. 6)Important part of job should be useable to the technician while fitting the jig. 7)The structure of jig should be simple so that even ordinary technicians can use it. 8)Adequate provision for supplying coolant or lubricant to the cutting tool should be there.

BOLTS
Bold text This is the most widely used fasteners, it is made up off metal rod. On its upper side, different type of heads are made to fix them on the remaining part, there are threads. Bolts are classified according to the type of head.

Types of Bolts 1)Hexagonal head bolts. 2)Square head bolts 3)Cheese head bolts 4)‘T’ head bolts 5)Hook bolts 6)Eye bolts 7)Cup head bolt 8)Counter sunk head bolt 9)Headless taper bolts

1)Hexagonal head bolts This bolt is most widely used six equal sides are made on its head. The sizes of the head is standard. It is made according to the diametric thickness of the bolt of different sizes. Its head is revolved with an ordinary double end or ring spanner. For convenience its head is chamfered the standard spanner fits well with head of the bolts. 2)Square head bolts Head of this head is square, it is use in such places where its head is gripped and neither moves nor allows the parts to move. Normally this bolts are fitted in a slots or where a square hole is present. There are some bolts whose lower parts below the square head is also made square. This fits in a slot or square hole and prevents from rotating. 3)Cheese head bolts At those places where there is inadequate space and there is difficulty in fitting the spanner, these type of bolts are used. These head are plain or round, but there is a pin below the head which saves if from revolving at the time of tightening the nut. 4)‘T’ head bolt This type of bolts are used in machine shop with the help of the bolts. This bolts are used as clamping source to a machine table. The head is rectangular and below it a square shape is made. 5)Hook bolt This is a special type of bolt. In this bolt instead of having a head there is an unthreaded end bent ‘u’ shaped or straight at right angles to the body of the bolt. It is used at places where there is a hole on one part with the other part job is to be held. 6)Eye bolt These bolt are specially fitted in heavy electric motors or other machines. It is a bolt provided with a hole or eye at hand, instead of the usual head. The eye receives a pin, stud or hook which takes the poll of the bolt. Their thickness is kept according to the weight of the machine. 7)Cup head bolt Head of this type of bolts is made from and sloping. The part below the head is square or 2 snug is made in it these bolts are fitted in square or sung groove and tighten with nut. These types of bolts are often used in wood work. These are also called rail track bolt because they are used on the rail lines. 8)Counter sunk head bolt It head is built in taper like counter sunk screw either a sung is made in its head or the part below head is made square. These types of bolts are used at places where the head is placed inside the surface of the job. 9)Headless taper bolt As per its name this bolt does not have a head and it is made in taper it is mostly used in coupling etc. It can be tightened without revolving it. '10) Foundation bolt' Generally the machine are fixed at appropriate place in the work shops in order to make them in stable manner they are fixed in the ground with the help of the foundation bolts. Bolts use for this purpose are of the following types. 1)Eye type foundation bolt 2)Rag type foundation bolt 3)Lewis type foundation bolt 4)Cotter foundation bolt

11) Eye type foundation bolt This foundation bolt is like the other eye bolts but it is greater in length. A slender bar of mild steel or wrought iron is heated and very easily its head is turned round in shape, while setting foundation of the machine in the eye hold of this bolt a mild steel bar is put across. Therefore the foundation is cemented and when the cement is set it is very difficult to extract it machine is fitted on these bolts and they are tightened with the help of nuts.

12)Rag type foundation bolt This type of foundation bolt are used for the foundation of heavy machines, leaving the threaded portion it is square in shape and bolts are made at its edges. Hoes are made in the ground below the holes of the root of the machine to be used in foundation and these bolts are hanged with the help of nuts mixture of cement and sand or zinc and sulphur is filled around it which tightly holdes to the ground. In order to tight holds to the ground in order to tight the machine again the nuts are tightened square head bolt or zigzing type foundation bolts also belong to this category.

13) Lewis type foundation bolt In this type of foundation bolt one side is straight and the other is in taper on the opposite side of the taped side a key is fixed mixture of cement and sand is fitted around it, if foundation bolt of this type is to be take out, first the key has to be taken out. This key is also some what tapered.

14)Cotter foundation bolt These type of bolt are also used for foundation of heavy machines these are also of special type. A plate is proved below the bolt in which grooves are cut for fitting cotter in order to keep the cotter plain washer is also used.

FASTERNER
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In all kinds of joining the various parts are held together by devices known as ‘fasteners’ and the elements by which the parts are so joined are called fasteners or fastening elements. There are three types of fastener used in Engineering practices they are 1)Temporary fasteners 2)Semi permanent fasteners 3)Permanent fasteners

1)Temporary fasteners Temporary fasteners are those in which reputed assembly or dismantling is possible without injury or destruction to the fasteners or to the parts. In temporary fastening the parts are held together such as screw, bolts, nuts, keys, cotters, pins etc bolts and nuts studs, and nuts screw are common example of fasteners.

2)Semi permanent fasteners Semi permanent fasteners are those which cannot be dismantled without injury or distraction to the fasteners. In semi permanent fastening parts are held together by riuiting or soldering. 3)Permanent fasteners Permanent fasteners are those in which both the fasteners and the members joined together must be destroyed while dismantling. Permanent fasteners may be welding.

Keys and key ways. We generally used a gear or a pully for moving another shaft through a shaft which is already in motion. Key and key ways are used to locate and secure and object in position such as gear or a pully with the help of key, gear or pully cannot move on their shaft but the shaft and the gear or the pully move together as one unit. A key is inserted between a shaft and a wheel in the key as way this makes the shaft and gear or pully as a one unit, Key ways are generally made up of good quality steel in order with stand the stresses. This keys are the in following forms; 1)Gib head key 2)Woodruft key 3)Feather head key 4)Round key

1)GIB HEAD KEY A gib head key is often considered suitable for all kinds of job and is the most popular key the stop face of gip head key is tape but its side are parallel. It is a rectangular cross section, its head is made towards its thick end and through which it can be easily taken out it is necessary that it remain fully tight other wise it can breaks become of job.

2)Woodruff key It is plain from one side and in half moon shape from the other side shaft contain the key way according to this key. This key is mostly used on small shaft a spindles of fast speed for classes of work.

3)Feather head key A feather key is of a rectangular section and is not tapered. It include 1)Plain head feather key 2) Pege feather key 3) Single head key 4) Double head key. i) Plain head feather key It is round and these are made long and rectangular. ii) Pege feather key It is similar to plain feather key but its end plain. A pege is made neer its centre. This is fitted in the hole made in the shaft so that the key cannot slip from the key ways. iii) Single head feather key This key is similar to pege feather key but its one end a head is made, there is hole in this head in which the screw is tighten which helps in keeping the key fixed. iv)Double head feather key In this type of keys, head are made on both the ends it is used to take help making the shaft moving with a hub into one unit. 4) Round head key This key is completely round and long, it filts half in the shaft and halft in the hub, this key can be parallel or tapper and the hub and the shaft is drilled accordingly. 5) Saddle key Under this key the following forms of key are included 1)Flat saddle key 2)Hollow saddle key

1)Flat saddle key Flat saddle key is fitted over the shaft, the place where the key is placed is made flat, it rest on this flat surface this type of key is used only for light load.

2)Hollow saddle key This is also used like flat saddle key but its surface is concave in shape. The diameter depends on the roundness of the shaft.

SEMI PRICISION MARKING AND MEASURING
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Introduction For laying out of the surface the job in coated to get the mark line clear to get clear and thin line the best layout medium should be selected.

The different types of marking media are; 1)White wash 2)Prussian blue 3)Copper sulphate 4)Cellulose lacquer

1)White wash White wash is prepared in many way. Chalk powder mixed with water Chalk mixed with methylated sprite White lead powder mixed with three pentine White wash is applied to rough forgings and casting with oxidize surface. White wash is not recommended for work pieces of high accuracy.

1)Prussian blue This is used on filed or machine finished surface this will gives very clear lines but taken more time for drying.

2)Copper sulphate The solution is prepared by mixing copper sulphate in water and few drops of nitric acid. The copper sulphate is used on filed or machine finished surface copper sulphate sticks to the finished surface well.

3)Cellulose Lacquer This is a commercially available marking media. It is made indifferent colour and dries very quickly. The only disadvantage is that it is very costly.

ANGLE  PLATE

Angle plate are used to support the job and to provide a vertical or angular plane for making. An angle plate is made of cast iron or steel and is machined accurately to an angle of 90. In same types, long slots are made to fix the jobs with bolts and nuts. Adjustable angle plates are available to support jobs in different angles. Angle plate can be used to support jobs in different angle. Angle plates are also used to set jobs on the machines.

SURFACE GAUGES

The surface gauges is one of the most common marketing tools used.

•Scribing lines parallel to a drum surface. •Setting jobs on machine parallel to a datum surface. •Checking the height and parallelism of jobs, setting jobs concentric to the machine spindle.

Types of surface gauges. Surface gauge / scribing blocks are on two types. Fixed and universal.

Surface gauge : Fixed type. The fixed type of surface gauges consists of a heavy flat base and a spindle, fixed upright to which a scriber is attached with a snug and a clamp nut.

Universal surface gauge. This has the following additional features. The spindle can be set to any position. Fine adjustments can be made quickly. Can also be used a cylindrical surface. Parallel lines can be scribed from any datum edge with the help of guide pins.

•Parts and functions of a universal surface gauge. Rocker arm The rocker arm is attached to the base along with a spring and a fine adjustment screw. This is used for the fine adjustment. Spindle The spindle is attached to the rocker arm. Scriber The scriber can be clamped in any position on the spindle with the help of a snig and a clamping nut. Base The base is made of steel or cast iron with a “V” groove helps to seat on circular work. The guide pins, fitted in the base are helpful for scribing lines from any.

MARKING OFF AND MARKING TABLE

Marking off Marking off or layout is carried out to indicate the location of operation to be done and provide guidance during rough machining or filing.

Witness marks The line marked on metal surface is likely to be erased due to handling. To avoid this, permanent marks are made by placing punch marks at convenient intervals along the marked line punch marks act as a witness against inaccuracies in machining and hence, they are known as witness marks.

Marking table A marking table (marking off table) is used as a reference surface for marking on work pieces.

Marking tables are made of cost iron or granite, and are available in various surface sizes, these table are used for setting measuring instruments for checking sizes parallelism and angles.

FILE SPECIFICATIONS AND GRADES. Files are manufactured in different types and grades to meet the various needs. Files are specified according to their length, grade, cut and shapes. Files are grade are determined by the spacing of the teeth.

1)A rough file -It is used for removing rapidly a larger quantity of metal. It is mostly used for trimming the rough edges of soft metal casting. 2)A bastard file --- is used in cases where there is a heavy reduction of material. 3)A second cut file --- is used to give a good finish on metals. It is excellent to file hard metals. It is useful for bringing the jobs close to the finishing size. 4)A smooth file is used to remove small quantity of material and to give a good finish. 5)A dead smooth file --- is used to bring to accurate size with a high degree of finish.

ELEMENTS OF A FILE Methods of material cutting The three methods of metal cutting are abrasion (1) fusion (2) incision. Filling is a method for removing excess material from a work piece by using a file which acts as a cutting tool. Files are available in many shapes and sizes. Parts of a file. 1)Face or side --- The broad part of the file with teeth cut on its surface. 2)Edge The thin part of the file with a single row of parallel teeth. 3)Heel --- The portion of the broad part without teeth. 4)Shoulder--- The curved part of the file separating tang from the body. 5)Tang --- The narrow and this part of the file which fits into the handle. 6)Handle --- The part fitted to the tang for holding the file. 7)Ferrule --- A protective metal ring to prevent cracking of the handle.

Cuts of Files The teeth of a file are formed by cuts made on its face. Files have cuts of different types. Files with different cuts have different uses. Types of cuts. Basically there are four types. 1) Single cut     2) Double cut     3) Rasp cut    4) Curved cut

1) Single cut A single cut files has rows of teeth cut in one direction across its face. The teeth are at an angle of 60 to the centre line. It can cut chips as wide as the cut at the file. Files with this cut are useful for filing soft metals like brass, aluminum, bronze and copper. Single cut files do not remove stock as fast a double cut files but the surface finish obtained is much smoother. 2) Double cut. A Double cut file has two rows of teeth cut diagonal to each other. The first row of teeth is known as OVERCUT and they are cut at an angle of 70. The other cut made diagonal to this is known as UPCUT and is at an angle of 51. This remove stack faster than the single cut file. 3) Rasp cut  The rasp cut has individual, sharp pointed teeth in a line and is useful for filing wood, leather and other soft materials. These files are available only in half round shape. 4)Curved cut file. These files have deeper cutting action and are useful for filing soft materials like aluminum, tin, copper and plastic. The curved cut files are available only in a flat shape.They are also known as vixen cut files.

LENGTH MEASUREMENT

When we measure an object, we are actually comparing it with a known standard of measurement. The base unit of length as per SL is the METRE. Length SI UNITS and MULTIPLES Base unit. The base unit of length as per the system international is the meter. The table given below lists same multiples of a meter.

METER (M) =   1000 MM CENTIMETER (CM) = 10 MM MILLMETER (MM) = 1000 MICROMETER (UM) = 0,00 1MM(MICRON)

ENGINEER’S STEEL RULE. When Dimension are given in a drawing without any indication about tolerance, it has to be assumed that measurement are to be made with a steel rule.

Steel rule are made of spring steel or stainless steel. The edges are accurately ground to form straight edges. The surface of the steel rule is satin – chrame finished to reduce glare and to prevent rusting.

Sizes to steel rules. Steel rules are available in different length, the common size being 150mm 300mm and 60mm.

The engineer’s steel role is graduated in 10mm, 5mm, 1mm and 0.5mm. The reading accuracy at the steel rule is 0.5mm.

Measuring with a steel rule The method of using a try square and a steel rule for accurate measurement. For accurate reading, it is necessary to read vertically and avoid errors arising out of parallax.

An experience person can transfer measurement from a steel rule very accurately. The steel rule graduations are accurately engraved with the line thickness ranging from 0.12 to 0.18mm.

TRY SQUARE.

The try square is a precision instrument which is used to check squareness (angles of 90) of a surface. The accuracy of measurement by a try square is about 0.002mm per 10mm length which is accurate enough to most workshop purpose. The try square has a blade with parallel surface. The blade is fixed to the stack at 90. Uses 1)Try square is used to check the squareness of machined our filed surface. 2)Check flatness of surfaces. 3)Mark lines at 90 to the edges of work pieces. 4)Set work pieces at right angle on work – holiday devices.

Try squares are made of hardened steel. Try squares are specified accordingly to the length of the blade i.e. 100mm, 150mm, 200mm.

JENNY CALIPERS Jenny calipers are used for marking and layout work. These calipers are also known as hermoporoclite. Caliper, add leg caliper, and leg and point calipers. Jenny calipers have one leg with an adjustable divider point, while the other is a bent leg. The legs are joined together to make a firm joint. Uses 1)Jenny calipers are used for making lines parallel to inside and outside edges locating the centre of round bars. 2)Calipers are available with the used bent leg or with a heel. Calipers, with ordinary bent legs, are used for drawing lines parallel along an inside edge and the heel type     is used for drawing parallel lines along outer edges. 3)Jenny calipers can also be used for scribing lines along curved edges while setting dimension and scribing lines, both legs should be of equal length. 4)The jenny calipers should be slignthly inclined while scribing lines. 5)While setting dimension for accurate setting the jenny caliper point should “click into the graduation”

Types of calipers Calipers are simple indirect measuring instrument used to transfer measurements from a steel rule to objects and vice versa. Calipers are of different types depending on the types of the joint and the shape of the leg. Types of joint The commonly used calipers are firm joint calipers and the joint and the shape of the leg.

Firm joint calipers. In the case of firm joint calipers both legs are pivoted at one end. To take measurement of work piece the calipers is opened roughly to the required size fine setting is done by tapping the caliper lightly on a wooden surface.

Spring joint calipers. Spring joint calipers have the advantage of quick setting the setting made without change unless the nut is turned. The size of a caliper is specified by its length, which is the distance between the private centre and tip of the leg.

Type of leg Outside and inside calipers are differentiated by the shape of the leg. Outside Calipers used for outside measurement. Inside Calipers It is used for internal measurement.

MARKING MEDIA Different marking media The different marking media are whitewash, Prussian blue, copper sulphate and cellulose lacquer.

Whitewash Whitewash is prepared in many ways 1)Chalk powder mixed with water 2)Chalk mixed with methylated sprit. 3)White lead powder mixed with turpentine.

Prussian Blue This is used on filed or machine. Finished surface this will give very clear lines but takes more time for drying than the other marking media.

Copper sulphate The solution is prepared by mixing copper sulphate in water and a few drops of nitric acid. The copper sulpahte is used on filed or machine. Finished surface copper sulphate sticks to the finished surface well.

Copper sulphate needs to be handle carefully as it is poisonous. Copper sulphate cating should be dried well before commencing marking as otherwise, the solution may stick on the instrument used for marking.

Cellular lacquer. This is commercially available marking medium. It is made in different colours and very quickly.

The selection of marking medium for a particular job depends on the surface finish and the accuracy of the work piece.

TYPES OF MARKING PUNCHES. Punches are used in order to make certain dimensioned features of the layout permanent. These are two types of punches. They are centre punch and prick punch.

Centre punch The angle of the point is 90 in a centre punch. The punch mark made by this is wide and not very deep. This punch is used for locating holes. The wide punch mark gives a good seating for starting the drill.

Prick punch The angle of the prick punch is 30 or 60. The 30 point punch is used for marking light punch marks needed to position dividers. The dividers leg will get a proper seating in the punch mark. The 60 punch is used for marking witness marks.

HACKSAW FRAME AND BLADE The hand hacksaw is used along with a blade to cut metal of different sections. It is also used to cut slots and contours.

Types of hacksaw frames The two different types of hacksaw frames are solid frames and adjustable frames.

Solid frame Only a particular standard length of blades can be fitted to this frame.

Adjustable frame (Tubular type) This is the most commonly used type. It gives a better grip and control, while sawing.

Hacksaw Blades. A hacksaw blades is a thin narrow steel band with teeth and two pin holes at the ends. It is used along with a hacksaw frame. The blade is made of either law alloy steel (CA) or high speed steel (HS) and is available in standard length of 250mm and 300mm.

Types of hacksaw blade. Two types of hacksaw blade are available all hard blade and flexible blade.

All hard blade These are hardened to the full length between the pin holes

Flexible blades For these type blade, only the teeth are hardened because of this flexibility these blades are useful for cutting along curved lines. Pitch of the blade The distance between adjacent teeth is known as the pitch of the blade. Classification					Pitch 1)Coarse					1.8 mm 2)Medium					1.4 mm & 1.0 mm 3)Fine						0.8 mm Hacksaw blades are designated according to their length pitch and types.

Setting of the saw To prevent the saw blade binding when penetvating into the material and to allow free movement of the blade. The cut is to be broader then thickness of the saw blade. This is achieved by the setting of the saw teeth. There are two types of saw setting.

Staggered set Alternate teeth or groups of teeth are staggered. This arrangement types for the free cutting and provide for good chip clearance.

Wave set In this the teeth of the blade are arranged in a wave form. For the best results, the blade with the right pitch should be selected and fitted correctly.

BENCH VICE Vices are used for holding work pieces, they are available in different types the vice used for bench work is the bench vice (Engineers vice) A bench vice is made of cast iron or cast steel and it is used to hold for filing, sawing, threading and other hand operation. The size of the vice is stated by the width of the laws. Parts of a bench vice The following are three parts of vice Fixed jaw, movable jaw, hand jaws, spindle, handle box nut and spring.

The box nut and the spring are the internal parts. Vice clamps or soft jaws. To hold a finished work use soft jaws (vice clamps) made of aluminium over the regular hand jaws. This will protect the work surface from damage.

Do not over tighten the vice as other wise the spindle may be damaged.

 SCAPER’S Introduction: the surface of certain machines parts which must run together very accurately are often finished by scrapping and the reason to do scraping is to removes high spot which are present often filing. When the surface is sliding over each other the high spots wear out quickly and the fit is turned into loose fit soon to avoid this the surface are often scraped to bring about much closer fit and as the result of this the parts which run together takes along time to wear out. Use of Scrapers: The scrapers are used to obtain more accurate and smooth surface which cannot be obtained by filing material. Scrapers are made of tool steel and high carbon is hardened and tempered the worn-out filing are also used as scrapers. Specification and classification Scraper are classified and specified according to the shape and the type. The commonly used scraper are flat, half round and triangular.

Definition: Scraper are being cutting tool which are used to finishing purpose to remove the high spot and to obtain a good flatness. This is made of tool steel hardened and tempered. Scrapers are similar like file but it has no cutting teeth on its body. It is completely smooth and point removing the metal by scraping only the cutting edge and the point of scraper is used to remove the metal. Scraper are available from 6 to 12 in metric from 150 to 300 mm and bigger size. Description types and uses. The most important type of scraper which are used for scraping various job are flat scraper half round triangular and hook scraper also double handle scraper are being used.

1)Flat scraper: This is very simple tool which is used to do scraping on flat surface. These shapes of this scraper is like a flat file for the end are ground to give sharp edge and also they are ground square to the end slightly taper. The scraper edge are slightly curved to prevent the corner of the scraper to contact with the surface being scrapped and marking deep scratches. Flat scraper has the handle to hold firmly and comfortable grip flat scraper is used for scraping or flat surface. It is available in length of 6” to 12” inches long and ¾ to 1 inch wise. 2)Half round scraper: The shape of this scraper is half round and it is bend towards the end. It is made up of tool steel is hardened and tempered H.K scraper is used for scraping half of bearing for bending in shaft and busher and convex surface it is available in it of 6” to 12” and 150 to 200mm. 3)Triangular scraper: The shape of this scraper is like triangle file making three shape edge. It is also taper towards the point this scraper is used for scraping small hole, key way groove, sharp corner’s and also used to remove the burs from the hallow. It is available in length at 6” to 12” and 150 to 300mm. 4)Hook scraper: this scraper is like flat file but the end is bent at right angle. This scraper being like as flat scraper it is used for scraping on flat surface the material is scraped by putting this scraper it available from 6” to 12” and 150mm to 30mm. 5)Double ended scraper: They are used for scraping bearing boxes and large curved surface, this scraper consists of two end and both end are used for holding while scraping.