1 Organization Structure Marketing HR GM MD&CEO Manufacturing Quality Engineering Finance R&D Sourcing Material Services Business Planning Internal Audit
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2 NO. OF DEPARTMENTS AND SHOPS 2.1 PRODUCTION Cold forging shop Machine shop Heat treatment shop Plating shop Press shop Material Testing Lab 2.1.1 Cold forging Shop In Cold forging shop, the forming of bulk material at room temperature with no heating of the initial slug or inter stages. The cold forming process is also volume specific and the process uses die and punches to convert a specific slug or blank of a given volume into a finished intricately shaped part of the exact same volume Fig 2.1.1 Layout of cold forging shop:
There are three sections in cold forging shop: 1. Bolt maker section In Bolt maker section production of various component carries out by Cold forging operation like
Cam brake 2
Swing arm Axle front wheel Axle rear wheel Shaft drive Pin gear shift lever
Bolt maker machines
BM-11 BM-10 NMB-3/8” NBM-SL BM-07 NEDSCHOFF BM-06 MAL MEDIE BM-05 NBM BM-04 CBM BM-03 NBM-01
2. Header section In header section there are various types of”studs” are formed which is used in engines. M8 * 205 stud acyl M7 * 201.4 bolt stud acyl M6 * 198 * M 7 BOLT A STUD M7 * 193.5 BOLT A STUD M8 * 140 BOLT STUD CYL M10 * 244 BOLT STUD CYL M10 * 238 BOLT STUD CYL Fastener section In Fastener section all the small parts such as nuts, bolts, screws etc. are formed which is used to joint or assemble the object or piece. Various fastener machines: 3
TKWARE 02 SASPI ROLLING SASPI BF 10B 3S CHUNZU ROLLING 02 CBF COLD 64S 02 CBF 64S 01 EWM ROLLING 03 NBM ¼”
Fastener products:
Joint break arm Notching of cam break Shaft comp. oil pump M5 * 10 bolt knock M10 * 30 hex bolt M8 * 31 flange bolt M8 * 60 hex bolt
2.1.2 MACHINE SHOP Introduction Computer Numerical Control (CNC) is one in which the functions and motions of a machine tool are controlled by means of a prepared program containing coded alphanumeric data. CNC can control the motions of the work piece or tool, the input parameters such as feed, depth of cut, speed, and the functions such as turning spindle on/off, turning coolant on/off. Section in the CNC shop: Gear assembly section Heat treatment section CNC working area
Modes of operation
4
Automatic operation: 1. Memory operation – The require program is already registered in the CNC memory. We can just select the program and start the operations. 2. MDI operation- In the MDI mode program Can be inputted in same format as normal programs and executed from the MDI panel. Mostly used for simple test operation. 3. Program restart- Restarting of a program for automatic operation from an intermediate point, a sequence no. is assigned to a block. MDI also usable as high speed program check function. 4. Manual handled interruption- movement by this operation can be done by overlapping it with the movement by automatic operation. 5. Sequence no. search- function is used to search for sequence no. within a program and to start the program from the block having sequence number.
Manual operation: Jog feed In the jog mode, a feed axis and directionselection switch on the machine operator’s panel moves the tool along the selected direction. The jog feed rate can be adjusted with the jog feed dial rate. Incremental feed In the incremental (STEP) mode, pressing a feed axis and direction selection switch on the machine operatorpanels moves the tool one step along the selected axis in the selected direction. Manual handled feed In the handled mode, rotating the manual pulse generator on the machine operator panel can move the tool. Manual absolute on and off
5
When the switch is turned on, the distance the tool is moved by manual operation is added to the current coordinates. Part programmer structure in CNC machine
Name of the program Selection of working plane, measuring system, units of measurement (mm or
inch). Defining and calling work origin Tool changing position First position (movement in working plane) and second positioning (movement in
spindle axis) for working, spindle start and coolant on. Third positioning for working (for mechanising, tool movement with tool radius
compensation) Depth of cut (in feed only) Definition of geometry preparation of profile (feeding of CNC drawing data Return to second position, spindle stop and coolant off Cancellation of fixed cycle, macro instruction, special command, tool radius
compensation Return to tool change position Movement in spindle axis and working plane. End of part program CNC PRODUCTS:
Kick shafts
6
Sprocket cam chain
Bearing races
Spacer & bushes
7
Fig 2.1.2 CNC Products 2.1.3 Heat treatment In Heat treatment shop cold-formed parts are subjected to heat treatment to improve the mechanical properties after the forming process or to eliminate undesirable properties. Heat treatment is any one of a number of controlled heating and cooling operations used to bring about a desired change in the physical properties of a metal. Its purpose is to improve the structural and physical properties for some particular use or for future work of the metal. There are five basic heat treating processes: hardening, case hardening, annealing, normalizing, and tempering. Although each of these processes brings about different results in metal, all of them involve three basic steps: heating, soaking, and cooling.
Heating Heating is the first step in a heat-treating process. Many alloys change structure when they are heated to specific temperatures. The structure of an alloy at room temperature can be amechanical mixture, a solid solution, or a combination solid solution and mechanical mixture. Soaking Once a metal part has been heated to the temperature at which desired changes in its structure will take place, it must remain at that temperature until the entire part has been evenly heated 8
throughout. This is known as soaking. The more mass the part has, the longer it must be soaked. Cooling After the part has been properly soaked, the third step is to cool it. Here again, the structure may change from one chemical composition to another, it may stay the same, or it may revert to its original form. For example, a metal that is a solid solution after heating may stay the same during cooling, change to a mechanical mixture, or change to a combination of the two, depending on the type of metal and the rate of cooling. All of these changes are predictable. For that reason, many metals can be made to conform to specific structures in order to increase their hardness, toughness, ductility, tensile strength, and so forth. Heat Treatment of Alloy Steel All heat-treating operations involve the heating and cooling of metals, the common forms of heat treatment for alloy steel are hardening, tempering, annealing, normalizing, and case hardening. Hardening Alloy steel is normally hardened by heating the metalto the required temperature and then cooling it rapidly byplunging the hot metal into a quenching medium, such as oil,water, or brine. Most steels must be cooled rapidly to hardenthem. The hardening process increases the hardness andstrength of metal, but also increases its brittleness. Tempering Steel is usually harder than necessary and too brittle for practical use after being hardened. Severe internal stresses are set up during the rapid cooling of the metal. Steel is tempered after being hardened to relieve the internal stresses and reduce its brittleness. Tempering consists of heating the metal to a specified temperature and then permitting the metal to cool. The rate of cooling usually has no effect on the metal structure during tempering. Therefore, the metal is usually permitted to cool in still air. Temperatures used for 9
tempering are normally much lower than the hardening temperatures. The higher the tempering temperature used, the softer the metal becomes. High-speed steel is one of the few metals that become harder instead of softer after it is tempered. Annealing Metals are annealed to relieve internal stresses, soften them, make them more ductile, and refine their grain structures. Metal is annealed by heating it to a prescribed temperature, holding it at that temperature for the required time, and then cooling it back to room temperature. The rate at which metal is cooled from the annealing temperature varies greatly. Steel must be cooled very slowly to produce maximum softness, This can be done by burying the hot part in sand, ashes, or some other substance that does not conduct heat readily (packing), or by shutting off the furnace and allowing the furnace and part to cool together (furnace cooling). Normalizing Alloy steel is normalized to relieve the internal stresses produced by machining, forging, or welding. Normalized steels are harder and stronger than annealed steels. Steel is much tougher in the normalized condition than in any other condition. Parts that will be subjected to impact and parts that require maximum toughness and resistance to external stresses are usually normalized. Normalizing prior to hardening is beneficial in obtaining the desired hardness, provided the hardening operation is performed correctly. Low carbon steels do not usually require normalizing, but no harmful effects result if these steels are normalized. Normalizing is achieved by heating the metal to a specified temperature (which is higher than either the hardening or annealing temperatures), soaking the metal until it is uniformly heated, and cooling it in still air. Case Hardening
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Case hardening is an ideal heat treatment for parts which require a wear resistant surface and a tough core, such as gears, cams, cylinder sleeves, and so forth. The most common case-hardening processes are carburizing and nitriding. During the casehardening process, low-carbon steel (either straight carbon steel or low-carbon alloy steel) is heated to a specific temperature in presence of a material (solid, liquid, or gas) which decomposes and deposits more carbon into the surface of a steel. Then, when the part is cooled rapidly, the outer surface or case becomes hard, leaving the, inside of the piece soft but very tough. 2.1.4 Metal plating and finishing
Metal finishing processes involve treatment of a metal work-piece in order to modify its surface properties, impart a particular attribute to the surface, or produce a decoration. Plating is a subset of such finishing operations that involves putting a coating of metal over a base metal substrate to give various desirable properties to the object. Metal coating is another subset of such finishing operations and involves the application of paint or powder coating to a metal work-piece. Products from metal finishing operations can range from structural steel to jewellery. The reason(s) for carrying out metal finishing can include:
decoration protection against corrosion providing resistance to oxidation, high temperatures, or UV radiation, imparting mechanical properties, such as resistance to fatigue, improvement of
ductile strength, or longevity, resistance to the use of abrasives, and, imparting electrical & thermal properties such as semi-conduction, thermal resistance, fire resistance,etc.
The main operations that can occur in metal plating and finishing are as follows: • Cleaning: including solvent cleaning (either cold soaking or vapour phase), aqueous cleaning, abrasive cleaning, and other types of cleaning such as 11
ultrasonic cleaning, chemical polishing and electropolishing. Cleaning is usually carried out before the main metal finishing operation and sometimes between operations. • Chemical and electrochemical conversion coatings: including chromating, phosphating, anodising, and colouring, “Conversion” refers to the fact that these processes involve changing or converting the surface layer to impart various properties to the surface. These processes are usually applied before painting to improve coating adhesion and provide corrosion protection. • Plating: electroplating of various types of metals onto metal surfaces. • Other metallic coating: including hot dipping (such as galvanising) and mechanical plating (such as the peening process used for Dublin’s ‘spire’). • Organic and other non-metallic coating: covers organic and other non-metallic coating and includes powder and liquid paints, resins and enamels. The coatings that have been applied are subsequently dried. This can be by leaving to dry in ambient air or assisted drying using an oven. • Stripping: used to remove previous metallic coatings from parts or to remove coatings from articles that have to be reworked.
Equipment used for Plating The type of equipment in use usually falls into one of the following two categories: • A series of process tanks and rinse tanks through which the work-pieces are passed, either contained in barrels in the case of bulk small items, or hung from racks or jigs in the case of bigger items. The majority of metallic coating operations and conversion coatings take place in such a set-up. • Spray equipment. This is mainly used in painting and other non-metallic coating operations. The majority of spray equipment would be manually operated. Automated spray equipment is sometimes used in larger 12
facilities. There are some applications involving flow or curtain coating, dip coating, or brush application Various chemicals used for metal plating
Zinc Cadmium Zinc dichromate Cadmium dichromate Galvanized Black zinc Phosphate, black phosphate Chrome Nickel Phosphate and oil
Description Zinc Cadmium Zinc dichromate Nickel Phosphate,
Plating
Corrosion resistance level
Zinc, electroplated Cadmium, electroplated
& other purposes Very good Very good, especially for
Zinc dichromate Bright nickel, electroplated black Manganese phosphate
wet environments Very good to excellent Good Good
phosphate Black zinc Zinc, electroplated Very good Table 2.1.4 Chemicals showing resistance against corrosion:
2.1.5 Material Testing Lab 13
LAB FACILITY INST & GAUGES CALLIBRATION INSPECTION WITH HEIGHT GAUGE PROFILE PROJECTOR SURFACE PLATE SURFACE ROUGHNESS TESTER
2.1.6 Lab Instruments Micro Vickers hardness tester Metallurgical microscope Standard Rockwell hardness tester Superficial hardness tester Eddy current tester Plating thickness testing gauges Salt spray chamber Abrasive cutter Profile projector Surface roughness tester 2.2 Product services 2.2.1 Tool room 2.2.2 Tool control cell 2.2.3 Production planning & control 2.2.4 Material Management & control 2.2.5 Quality Engineering 2.2.5 Maintenance
3.1 PROJECT INTRODUCTION
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“Studied everything in brief about production of various Products in Cold Forging Shop” 3.1.1 Background Cold forging is a process in which the shape of metal is changed, by mechanical forces only, using the ductile properties of metal. In forging, a metal work piece is Plastically deformed by pressing, squeezing, or hammering forces – at temperatures ranging from ambient (cold Forging) to 1,500oC (hot forging). During forging, the material should have sufficient flow properties and work at the upper limit of the material’s potential strength so as to Fill the die cavity shape without resulting in cracks in the material. The properties of the worked metal can be greatly enhanced by selecting the proper types and Sequence of operations. The controlled process of deformation that takes place imparts exceptional metallurgical soundness and mechanical properties to The forging – structural integrity, impact strength, fracture toughness, fatigue life and uniformity. Forging is a cost effective way to produce net-shape or near-net-shape components. Virtually all metals can be forged. This makes an extensive range of physical and mechanical properties available in products with the highest structural integrity. Forgings are used in high performance, high strength, and high reliability applications where tension, Stress, load, and human safety are critical considerations. They are also employed in a wide range of demanding environments, including highly corrosive, and extreme temperatures and pressures. 1 Trends in Forging One of the most important subjects of research and development in forging is precision forging where high accuracy, complex and net shape components can be produced. Cold forging has high potential to reduce manufacturing cost. If the work material could be completely filled up into the die cavity, desired
15
accuracy of the product could be achieved, and hence high productivity could be envisaged. However, the complete filling up of material into the die cavity is quite difficult because of high working pressure. The process often involves uni/multi-axial loading, large deformation and substantial work hardening of the work material in order to achieve the required shape. Hence, punch and die used in cold forging often need to withstand forming stress up to 1500 N/mm2. 2 Basic Consideration (Principles) The working pressure (loads) in forging consists of the following three principle components. 1. Resistance for ideal deformation 2. Frictional resistance 3. Resistance for redundant work (inhomogeneous material flow) 3 Working Limits “Problems” The working pressure in cold forging is so high that the sufficient depression of the work materials to attain the desired accuracy of the products cannot be practised within the allowance of tool strength. Therefore, the reduction of the working pressure is the most important problem for the improvement of the accuracy of the forged products. When complete filling of the material into the die is targeted, the working pressure will increase rapidly, resulting in die breakage 3. However, if working pressure is reduced within the die strength allowance (approx. 250 Kgf/mm2), unfilled portion will remain in the product. 4 Principle of Working Pressures When a workpiece material is specified, the working pressure for ideal deformation is governed by the fractional reduction in area R as shown in Figure 1.
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Closed die forging without flash is essentially impossible to complete the filling up of the material into the die cavitybecause becomes unity at the stroke end, and hence the working pressure increases infinitely. Therefore, in order to avoid a steep increase in working pressure, a flow relief portion must be prepared at some unnecessary locations of the contour even when the complete filling up of material is attained at necessary contour portions. 3.1.2 Cold Forging Process 1 Cold Heading One of the most important cold forming techanics is cold heading. Basically it is the reshaping of unheated metal by streaking holeson a length of wire inserted in a die. The force of the blow creates enough pressure to cause the metal to flowoutward unrestricted into a die cavity. The h eadoer upset portion of part generally is larger in diameter then the original blank, and the length has been decreased. Generally speaking normal cold heading permits of about two and half times the diameter of wire in a single blow as diagrammed in figure 1.improved techanics and minor tooling changes can increase this ratio to a limited shown in fig. 2.1.
FIG 3.1.2(a) Cold heading
2 Trimming
17
For parts having other than round heads, an additional heading operation called trimming is performed.a typical operation is cold forming hex-head cap screws,such as the one shown in fig.
Fig 3.1.2(b) Trimming 3 Piercing A final operation in the
heading sequence for making nuts
is piercing in which the
hole is punched out as a step prior
to threading.
Fig 3.1.2(c) Piercing
4 Extrusion Extrusion, as it applies to cold heading , is the forcing of the metal into the die smaller in diameter than that his is a the original wire stock, which increases its wire length, as illustrated in fig. 7. This is an efficient and highly economical method for creating two or more diameters in part being formed. Also, increasing the ratio of head-to-shank size beyond the normal cold heading capability is possible as shown in the examples in fig. 8 and 9.
18
Fig 3.1.2(d) Extrusion 3.1.3 Cold Extrusion Cold extrusion technology the forming of part to thr desired size and shape by moving the metal at room temperature into a die. sufficient force is required to exceed the yield strength of the stainless steel. Plastic deformation results which enables the metal to fill out the die cavities to extremely close tolerances.althoughther are many cold extrusion operation all are variation of one or more of the following: 1 Forward Extrusion It forces the metal to flow in the same direction as the descending punch and through a hole in the die to form a required shape and dimensions as shown in the figure. Forward extrusion is especially useful in the production of bolts and screws, stepped, shafts, and cyclinders. 2 Backward extrusions It forces the metal to flow upward around the descending punch. Extrusion pressure are generally higher and slug preparation is more critical. 3 Cold forging drawbacks
Potentially higher contact stress that may cause tool fail or excessive tool
deflection Probable fracture due to deformation limit of cold material
19
3.1.4. DESIGN CONSIDERATION FOR COLD FORGING 1 Product Design Stage: The engineering design team finalise the geometry, dimension, tolerance and materialfor the final component. This is based on intended application in the desired performance characteristic for the particular part. The service, including typical output is a machine drawing of the final required part; which include post forging operations such as machining, tolerance and surface finish requirements. The machine drawing of the considered component is shown in Fig. The first step for a production engineer to convert the machine drawing into forging part drawing. Understanding of the function of actual part in service can be considered as a prerequisite to efficiently handle this conversion phase. This understanding also improves thedecision making ability for the subsequent design stages. Once get approval from the customer on a design, move forward with the process. We have a series of companystandards that are product specific, but we use them to create a blueprint of the part. The same requirements and tolerances get put on the parts. These drawings are found at every machine as the product is made. It gives the guys on the floor a reference point so that they know exactly what we’re putting together. Engineering and manufacturing work together, and by very aggressively marrying the
20
two together, we’ve given the customer something extra.
Fig 3.1.4 Machine Drawing Of the Component 2 Die Design Stagegn
Stage:
There are no fixed rules for designing the dies for forging. The design method adopted is majorly dependent on the geometry of component and the processing conditions. There are, however, a set of recommended guidelines and principles for design, which can be adopted based on a particular situation. They are mostly empirical, and are developed from years of practical experience. With the recent developments in virtual process simulation using finite element method; these adopted guidelines can be further refined to suit the exact scenario. In case of cold forging, the design phase follows the following steps: Determination of Parting line and Axis of Product for Manufacturing: This step is crucial as it impacts both component quality and the method of die design. As per the stated guidelines, the selection of parting line should be such that: a) Deep impressions in the die are avoided to improve die life. 21
b) Die side thrust is minimised, to avoid die shift during the forging cycle. c) Largest periphery is preferred to be placed around the parting line; so that it is easier to force metal laterally to spread into the cavity. Putting the largest flat surface on the parting line is the other variation of this criterion. d) Desired grain orientation is achieved for the part to be manufactured. In order to improve the mechanical properties of the component, it is desirable that the grainflow orientation is perpendicular to the loading direction. This will improve the fatigue resistance of the component. Thus, reviewing the actual application of the component, one could select the parting line.
3 Decide the numberof stages for forging The key terms to remember in the process are the number of dies used in the process, as well as the number of blows. Dies are used to form the shank of the part. Conversely, blows are the number of “punches” that strike the part.Tooling lined up opposite the dies performs the punches. The cold-forming machine punches the metal in the die to mold the part. Once we have the dies andtooling set up, we’re able to put material out at a rapid rate. The key is identifying how many dies or punches are needed to perform the operation. If you attempt to manipulate the material too much in any single die or punch, you can negatively affect the properties of the metal. So it really is a balance to achieve efficient manufacturing using the fewest steps, while also preserving the tensile strength of the Metal.
Single Blow Header
22
Fig 3.1.5(a) Single Blow Header Single-blow headers are the simplest and fastest. They can produce hundreds of pieces per minute but are limited to minor shank extrusion and simple head shapes. In singlestroke machine, wire is sheared to length, transferred to a die , struck one blow, and ejected. Single-blow headers are adequate when head diameters or volume is relatively small, and the materials lends itself easily to upsetting. Double Blow Header
Fig 3.1.5(b) Double Blow Header When two blows are used to form the shape, the first punch starts the metal flow in a given direction so the desired shape can be completed with the second blow, as shown in figure. The punches oscillate between blows to one die so that a finished part is produced with every other stroke.
Multiple-Die Machines 23
Fig 3.1.5(c) Multiple Die Machine Where additional strokes are required for more intricate contours, multi-station or progressive headers are used. On such machines, parts are mechanically transferred from one die to next, and all stations work simultaneously so that a part is finished and ejected at each stroke.
3.1.5 Thread rolling Thread rolling consist of nothing more than passing around section of cold finished stainless steel between two special roll-threading dies, which are mounted in a machine in such a way as to make a material move in a through- feed manner. The surface materials stressed beyond its yield strength, causing it to flow plastically out of place to form the root groove sand crests. Roll threaded parts have better strength properties and better wear resistance then similar parts that have been machined.
Fig 3.1.5(a) Thread Rolling
1 Applications Of Threads 24
The general applications of various objects having screw threads are :
fastening : screws, nut-bolts and studs having screw threads are used for
temporarily fixing one part on to another part joining : e.g., co-axial joining of rods, tubes etc. by external and internal screw
threads at their ends or separate adapters clamping : strongly holding an object by a threaded rod, e.g., in c-clamps, vices,
tailstock on lathe bed etc. controlled linear movement : e.g., travel of slides (tailstock barrel, compound slide, cross slide etc.) and work tables in milling machine, shaping machine, cnc
machine tools and so on. transmission of motion and power : e.g., lead screws of machine tools converting rotary motion to translation : rotation of the screw causing linear
travel of the nut, which have wide use in machine tool kinematic systems position control in instruments : e.g., screws enabling precision movement of
the work table in microscopes etc. precision measurement of length : e.g., the threaded spindle of micrometers
and so on. acting as worm for obtaining slow rotation of gear or worm wheel exerting heavy force : e.g., mechanical presses conveying and squeezing materials : e.g., in screw conveyor, injection
moulding machine, screw pump etc. controlled automatic feeding in mass production assembly etc.
2 Production of threads by thread rolling In production of screw threads, compared to machining thread rolling, • is generally cold working process • provides higher strength to the threads • does not cause any material loss • does not require that high accuracy and finish of the blank • requires simpler machines and tools • applicable for threads of smaller diameter, shorter length and finer pitch • enables much faster production of small products like screws, bolts, studs etc. 25
• cannot provide that high accuracy • is applicable for relatively softer metals • is used mostly for making external screw threads • needs separate dies for different threads Thread rolling is accomplished by shifting work material by plastic deformation, instead of cutting or separation, with the help of a pair of dies having same threads desired.. Different types of dies and methods are used for thread rolling which include, • Thread rolling between two flat dies • Thread rolling between a pair of circular dies • Thread rolling by sector dies
Fig 3.1.5 (b) Rolling of external threads by flat dies
Flat dies The basic principle is schematically shown in Fig. 3.1.5(b). Flat dies; one fixed and the other moving parallely, are used in three configurations : Horizontal : most convenient and common Vertical : occupies less space and facilitates cleaning and lubrication under gravity Inclined : derives benefit of both horizontal and vertical features
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All the flat dies are made of hardened cold die steel and provided with linear parallel threads like grooves of geometry as that of the desired thread.
Fig. 3.1.5(c)Principle of thread rolling by flat dies
Rolling defects and their causes
Very irregular thread with deformation of teeth Rollers are not synchronized Feeding is inclined respect to the axis of the rollers Material not suitable for cold rolling Rollers overload Blanks surface with excessive rough
Irregular helix of thread
Rollers are not synchronized Feeding is inclined respect to the axis of the rollers Rollers imperfect
Threads with wrong size Outside and
Diameter of blank oversized
medium diameters both oversized Oversized medium diameter and exact
Diameter of blank oversized. If the thread
outside diameter
of the piece is complete, the thread of the
Medium diameter oversized and
roller is not deep enough Insufficient pressure of the rollers. If the
undersized outside diameter
thread executed is complete, the thread of
Exact medium diameter and oversized
the roller is not deep enough Oversized diameter of blank. Thread of
outside diameter
the roller deeper than necessary 27
Exact medium diameter and undersized
Undersized diameter of blank. If the
outside diameter
thread executed is complete, the thread of
Undersized medium diameter and
the roller is not deep enough Excessive pressure of the rollers. Thread
oversized outside diameter Undersized medium diameter and exact
of the roller deeper than necessary Undersized diameter of blank. Thread of
outside diameter Outside and medium diameters both
the roller deeper than necessary Undersized diameter of blank.
undersized
3 Advantages and disadvantages of thread rolling This type of processing has advantages and disadvantages, so that its adoption should be carefully considered. The advantages can be briefly listed as: 1. Speed and efficiency. The thread rolling process is undoubtedly the fastest to execute threads in a wide range, and in fact, in some cases you can get to production of over a thousand pieces per minute. The appropriate use of autoloaders also allows a single operator to control multiple machines with a considerable saving of manpower. 2. Material savings. Since there is no generation of chips, you get a slight economy of material: lower in smaller sizes, greater in larger diameters. They are also not ecological problems related to disposal of oil soaked chips. 3. Improvement of technological properties. Since the fibers of the material are not cut as in conventional methods, but plastically deformed and forced to follow the contours of the thread, there is a general improvement of all the technological characteristics. The tensile strength, in rolled products in general, is about 10% higher than the normal . The resistance to torsion is significantly increased, and finally the resistance to stress, given the greater smoothness of the surfaces of the threads, which ensures a better grip, increase of about 75%. 4. Accuracy. With the rolling of threads you can get high precision thread, suitable for every application, but only if that the roller dies are carefully constructed and that the blanks are properly prepared. 5. Uniformity of production. The rolling dies (or the rolling racks) are not reground and retain their original profile until the entire band is not seriously damaged 28
(almost always with more or less extensive chipping). So the threads are produced by thread rolling have an very uniform size if the blanks have constant diameters and that the material always has the same characteristics. Consequently, the dimensional control of parts produced may be limited to a small percentage. 6. Smoothness. Browning due to compression and friction of the dies on the parts, cause slight surface hardening and a remarkable improvement of the roughness of the surface of the thread generated, improving its strength. Besides these advantages, however, there are a number of disadvantages that can be as listed: 1. High cost of the rolling dies: This factor makes it uneconomic rolling of a limited number of pieces. 2. Parts with cavities. They are easily deformable under the pressure of the dies and thus can not be rolled. 3. Materials with low ductility. Can not be rolled material having a coefficient of less than 8% elongation. 4. Hard materials. Materials with a hardness exceeding 35 HRC are extremely difficult to roll. 5. Depth-diameter ratio of the thread. When the depth of the thread is over 15% of the diameter, the roll is very difficult because the pieces after rolling, are distorted. 6. Preparation of the blanks. Since this procedure is based on a movement of a definite amount of material, the accuracy of the various diameters of the thread, depends largely on the precision with which he prepared the diameter of prerolling. It is therefore necessary that the diameter of the workpiece to be rolled is contained in the tolerances at least equal to those required by the finished part. So operations are required to prepare a little more complex than those required for other methods of generation of the threads.
3.2 Raw Material selection 29
3.2.1 Introduction Especially grades of stainless steel and other specialty alloys have been designed for virtually every cold heading, forming, upsetting, and extruding operation. They are necessary for the growing number of fastener components that must have the corrosion resistance and strength to withstand harsh environments, high operating temperatures, and great pressures, as well as requirements for special magnetic properties. For all such components, alloy selection has also been governed by the need to reduce part costs and secondary machining operations, thus improving productivity.
Material quality requirements
These process characteristics necessitate a proper manufacturing quality of cold forging quality wire rod. The important features of these quality requirements are
as under: Excellent surface quality ensuring zero defect situation so that forged
components have no defects. Good control over quality to ensure smooth forging processes. Good control over mechanical properties such as tensile strength and reduction
area to ensure proper cold forgeability and productivity. Completely descaled surface to avoid forging defects such as scale pits and
resultant surface roughness. Suitable metalurigical structure to ensure proper machinability level
3.2.2 RAW MATERIAL USED IN COLD FORGING
Alloy Steel Boron Steel Carbon Steel
Table 3.2.2 Chemical Composition Of Typical Cold Forging Quality Grades 1.CARBON STEELS SR.N
GRADE
C%
SI
MN
S
P 30
CR
B
MO
PB
NI
O 1.1
AISI100
0.06
%
%
%MAX
%MAX
.10
.
.05
.04
.05
.04
.05
.04
.04
.03
.04
.03
6 1.2
0.10
.10
8
1.4
1.5
0 .
.10
0 .
AISI101
.
0
08-.
30-.6
VS1425
13 .
0 .
0
10-.
21-.4
VS13111
14 .07-
5 .
.13
.07
0.11
20-.4 .15
0 .30-
.05
.04
.10
60 .
.05
.04
.26-.35
.04-.09
AISI101
0.13
1.7
5 AISI101
-.18 0.15
8
-.20
60-.9
.
0 .
EN1AL
.10
08-. 1.9
%
%
%
30-.5
1.6
1.8
%
25-.4
AISI100
1.3
%
EN1A
15 . 07-.
.
85-.1 .10
.15 .80-
25-. 35 .20-.30
.06
1.20
15
2. BORON STEELS SR .
GRADE
C%
SI
MN
%
%
S%
P%
CR%
B%
MO %
31
PB%
NI %
2.1
AISI 10B21
.
.30
.03
.03
.10-.20
.0005-.003
.03
.03
.10-.20
.0005-.003
.03
.03
.30-.40
.0006-.003
.03
.03
.10-.20
.0006-.003
.03
.03
.20-.40
.0006-.003
.
.
.
.90-
.0015-.005
34-.3
60-.
015 015 1.20
8 .
90 .
.
34-.4
35-.
025 025 1.15
0
50
18-.2 2.2
AISI 15B25
3 .
1.10 .30
23-.2 2.3
8 DIN 19MNB4M .
AISI 15B41
5 .
.30
AISI 10B36M
4 .
.30
2.7
DIN 36CRB4
AISI 51B35M
9 .
1.35 -
.30
34-.4 2.6
.801.10
36-.4 2.5
.901.30
20-.2 2.4
.80-
1.65 .801.10
.10
.30
.
.90-
.0006-.003
.10
.15
3. ALLOY STEELS
SR 3.1
GRADE SCM 415H
C% .12-.18
SI%
MN
.
% .
15-.
55-.9 32
S%
P%
CR% B
MO%
% .03
.03
.851.25
PB
NI%
% .15-.35
.25
3.2
3.3
3.4
3.5
35 .
0 .
15-.
55-.9
30 .
0 .
15-.
70-.9
30 .
0 .
4
10-.
45-.7
AISI 4140
35 .
0 .
15-.
45-.7
30
0
SCM 435
AISI 4135
EN 2
.32-.39
.33-.38
.35-.45
.38-.43
.03
.03
.80-
.15-.35
1.25 .04
.035
.80-
.301.80
.15-.25
.25
.15-.35
1.3-
1.10 .04
.035
.901.40
.04
.035
.80-
1.8 .15-.25
1.10
3.3Selection of die material 3.3.1 Introduction Closed die forging dies are usually made from low-alloy, pre-hardened steels containing 0 35-0 50 % carbon, 1 50-5 00 % chromium, and additions of nickel, molybdenum, tungsten, and vanadium It is difficult to heat treat die blocks safely after machining because thermal distortion could destroy or reduce the dimensional accuracy of the cavity Therefore, die blocks are machined after the desired hardness has been achieved through heat treatment Die blocks containing shallow or simple cavities can be hardened to Rc 50 However, die blocks with deep cavities, nbs, or complex design require relatively softer, tougher materials to minimize cracking and die breakage when the volume of parts is high and the size of the forging is limited, die inserts can be incorporated in the die block to minimize wear Inserts are generally installed in locations that are prone to excessive wear due to complexity of design and material flow. Table 3.3.1 Recommended die block materials for forging various materials
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Material
Application
Die Material
Hardness, Rc
Forged Aluminium
Brass
Punches, die
H11,H12,H13
44-48
Die inserts
H11,H12,H13
46-50
Punches, dies
H21,H11,H13
48-52
H13,H12,H19
38-48
D2, A2 or hardweld
58-60
And inserts
Punches, dies, Steel
And inserts
on cutting edge of Trimmer dies
cold-rolled steel
3.3.2 Die Blocks Production of forgings is normally earned out with a pair of die blocks on which both cavities are machined The layout of the cavities on die blocks has to be designed to satisfy the following conditions: 1 The die block should be the minimum size possible but strong enough to sustain the forging loads foi the lequired production run 2 Tilting of the die block caused by off-centie loading should be minimized 34
Causes Of Die Failure Mainly, there are three basic causes of die failure, 1 Overloading Overloading may cause rapid wear and breakage It can be avoided by careful selection of die steel and hardness, use of blocks of adequate size, proper application of working pressures, proper die design to ensure correct metal flow, and proper installation of the die in the press machine. 2 Abrasive action Abrasive caused by the flow and spreading of hot metal in the cavity of a forging die abrasion is particularly severe if the design of the forging is complex or in other respects difficult to forge, if the metal being forged has a high strength Abrasion can be eliminated or minimized by good die design, good lubricant, careful selection of die composition and hardness, and proper heating 3 Overheating As a die becomes hotter, its resistance to wear decreases Overheating is likely to occur in areas of the die cavity In addition, overheating may result from continuous production. 3.3.3 Die analysis The process used to analyze the previous die is also used for this die.The elastic-plastic FE package (LUSAS) is used to find out whether the die would sustain the forging load or not The same technique is used to applying the loads The force vectors produced by the simulation package and illustrated in Fig 6 25, at the last stage of the forging process are subjected to the inside of the die cavity The load from the press machine is considered as a prescribed displacement acting on the surface in contact with the machine ram towards the die cavity Due to the symmetry of the die along the vertical axis and the similarity of the two halves of the die set, just one half of the top die is considered A mesh system is created with 230,3-node elements connected together 35
with 149 nodes The elements m the region close to the cavity are made finer and coarse elements are created in the regions away from the die cavity where the expected stress is not large Irregular type of meshing is selected from MYSTRO options, because it is more flexible for complex shapes.
3.4 Lubricants 3.4.1 Introduction to Lubrication Lubrication is of great importance in forging operations to reduce friction between the die and the workpiece. Considering the importance of lubricants in the deformation processes, it is amazing that no account of their use can be found until relatively recent times. This can be attributed to the fact that the composition, manufacture, and use of lubricants were - and to some extent, still are - closely guarded secrets. Additionally, it is quite possible that lubricants assumed a vital role only at a later stage of development of forging as technology. Effective lubrication provides better surface finish, die life and workability. Two of the most significant lubricant developments occurred during World War II. The phosphate conversion coating was adopted in Germany for severe cold deformation (such as drawing and extrusion) of steel. These developments are in practice even today. 3.4.2 Classification of lubrication mechanisms In forging, as in most other metal forming operations, friction modeling is complicated by the fact that any of several different regimes of lubrication can exist at the billet-die interface. Lange [5] classifies the lubricating mechanisms as:
36
1 Dry interfaces Under "dry" conditions, no lubricant is present at the interface and only the oxide layers deposited on the die and workpiece materials may act as a "separating" layer. In this case, friction is high, and such a situation is desirable in only a few selected forming operations, such as hot rolling of plates and slabs and nonlubricated extrusion of aluminum alloys. This kind of a situation is desirable because it allows the rolls to get a better grip of the workpiece.
3.4.3 Characteristics of ideal lubricants In metal forming, friction is controlled by the use of appropriate lubricants forgiven applications. There are some attributes that are generally valid for the majority of applications, based on an evaluation by Schey [4]. In forging, the ideal lubricant is expected to: • Control friction - Reduce sliding friction between the dies and the forging inorder to reduce pressure requirements, to fill the die cavity, and to control metal flow. • Separation of surfaces - Act as a parting agent and prevent local welding and subsequent damage to the die and workpiece surfaces. • Reduced Wear - should reduce wear of die while limiting wear of workpiece material to tolerable proportions. • Protection of old and new surfaces - should cover both old and new surfaces generated during deformation efficiently by possessing wetting and spreading characteristics.
37
• Adaptability to varied working conditions - Function at varying pressures, temperatures and relative sliding velocities. • Thermal Insulation - Possess insulating properties so as to reduce heat losses from the workpiece and to minimize temperature fluctuations on the die surface. • Rapid response - should exert its influence in a short time (order of a few milliseconds.) • Durability of liquid film - Capable of withstanding continued or repeated encounters. • Cooling − Also function as a coolant in high rate forming. • Stability - Should be unaffected by temperature, oxidation, contamination, bacteriological attack, etc.. • Reactivity - Should not be corrosive to the dies or workpiece. • Harmless residues - Should not cause unwanted physical, chemical or metallurgical changes in the products. • Application and removal - Should be easy. • Disposal - Should be possible to reclaim some lubricant and easy to treat effluents. • Cost - Commercially available at reasonable cost. • Handling and Safety - Non toxic, non carcinogenic, etc.. • Integrated Approach - As part of the activity of technology. • Cover the die surface uniformly so that local lubricant breakdown and uneven metal flow are prevented. • Be free of residues that would accumulate in deep impressions.
38
• Develop a balanced gas pressure to assist quick release of the forging from the die cavity; this characteristic is particularly important in hammer forging, in which ejectors are not used. No single lubricant can fulfill all of the requirements listed above; therefore, a compromise must be made for each specific application. Various types of lubricants are used, and they can be applied by swabbing or spraying. The simplest is high flash point oil swabbed onto the dies. Colloidal graphite suspensions in either oil or water are frequently used. Synthetic lubricants can be employed for light forging operations. The water-base and synthetic lubricants are extensively used primarily because of cleanliness. In addition, no single test method can evaluate all of these characteristics simultaneously. Therefore, various testing methods exist for evaluation of one or more lubricant characteristic 3.4.4 Selection criteria for industrial lubricants Some of the criterion used for industrial lubricant selection is : Tooling: What is the die alloy? How hot will it get? How complex is the die? Workpiece: What is its composition? What is its proper forging temperature? Forging equipment: Die ?Punch?Type and size/capacity? Forging sequence: Number and type of die stations? Function of each? Cycle times? Lubricant used: Perceived advantages? Disadvantages? Application methods used. Lubricants have to be chosen based on the operating temperatures, relative velocities of workpiece and die, interface pressures, adhesion to the materials involved and the lubricant regime under these conditions. Therefore lubrication in hot forging and cold forging are different, the former in the regime of solid-film and the latter in the regime of mixed-film. Hot forging involves less pressures and higher temperatures than cold 39
forging. Table shows some typical lubricants used in hot and cold forging. Schey has described extensively different lubricants, their constituents, application, and etc. 3.4.5 Lubricants used in Microturner The great variety of processes calls for a yet larger variety of lubricants, and their operative mechanisms are best discussed according to workpiece temperature, starting with the simpler cold forging mechanisms and progressing to the complexities introduced by higher temperatures. A brief review of the different lubricant types used and their application in the different lubrication regimes and forging processes is presented.
1 Oil-base lubricants Mineral oils obtained from the distillation of crude oils (or their synthetic equivalents) provide the base for many well-established industrial lubricants. Their viscosity is usually chosen to assure predominantly hydrodynamic lubrication at the existing velocities, pressures, temperatures, and during plastic deformation even in cold working, and this leads to a reduction in their viscosity, counterbalanced by the usually exponential increase in viscosity with pressure. Above some critical pressure, oils become solids and behave as a polymer film would. In cold working, lubrication is mostly of the mixed-film type and additives are almost invariably incorporated to protect against direct metal-to-metal contact at asperities. The types of additives depend on the workpiece and die compositions and on the severity of the operation. Different additives enable use of oil-base lubricants for boundary and EP regimes over a wide temperature and pressure range. Natural oils, fats, etc. offer a wide range of viscosity, relatively low solidification pressures, and usually also contain some free boundary agents. When their viscosity is too high, they may be deposited from a volatile solvent as is done with lanolin in the coating of Al slugs for cold extrusion. All oils ignite at their flash point and while the residue may lubricate, especially if the oil 40
contains additives, the resulting pollution is objectionable and has led to a diminishing use of oil-base lubricants for hot-working processes.
3.5 Study of Machine (NBM) 3.5.1 Introduction Boltmaker is a machine which carries cold forging operation for the production of components like cam brakes,axle,bolts etc. the machine on which i worked is national boltmaker 1”.the mechanism of machine is cold forging which is carried out by using die-punch of various size as per the requirement. The m/c moves with the help of pulleys of different sizes which gives feed to the m/c and electric motor gives drive to the pulleys. The commands to the m/c is given from the panel by the operator to run the m/c.the panel consist of many controls like to start/stop machinec,start/stop electric motor etc .The m/c uses raw material of minimum 12mm to 25.4mm for the production of components. During this one week of my training m/c two components were made on i.e cam brake and axle. Machine Parts
taper wage taper plate punch block punch stopper cutter quill die block die die plate transfer finger finger arm 41
transfer cam kick out bed pin bush feed roll wire stand electric motor oil motor control panel
3.5.2 Products The boltmaker 1” basically produce 3 components as follows:1. cam brake 2. front axle 3. bolt etc.
Raw Material Raw material used for the production of these components is alloy steel material called as warm steel wire.for different components different dia sizes are used. 1. for cam brake:- dia 15.70mm is used. 2. for axle:- dia 17.50mm is used. 3. for bolt:- dia 11.68mm is used. Cam front brake
Fig 3.5.2 Cam Front Brake
42
Cam brakes are used in motor bikes.the cam brake rotates and pushes rollers located on brake shoe against drum. Cam brake is produced from the warm steel wire of dia 15.70.the length of 68.50mm from the feed is cut at the cut off with the cutter and is made to pass through four die-punch to produce final component as per requirement. Our customer for this product is Bajaj autos, hero moto corp. etc.
Procedure Of Cam Brake For the production of cam front brake the raw material of dia 15.70 is taken from wire stand and with the help of feed it is send into the m/c where it comes upto quill. Quill helps to keep the wire straight and it carries the wire upto the stopper. Stopper is set according to the requirement. When piece comes upto the stopper, cutter cuts the wire as per the requirement and then finger collects it from there and takes it to die #1 and holds it till the punch #1 comes and pushes the wire into die. When the piece gets inside the die then with the help of kick out and pushing rods the piece comes out of the die and then finger collects it from there and take it to die #2 and holds it there till the punch #2 comes and punches the piece into die #2 and then same procedure continues till the piece passes through die # 4 and then pushing rod pushes the piece out of the die and with the help of conveyer piece is collected in the bin kept under the conveyer belt.
3.5.3 Die And Punches Used Dies and punches used for the production of cam brake are made of carbide material. The die is put into the die case and the punch is put into the punch case. All the punches and dies are put into die and punch block respectively. Punch case consists of punch pin of 90mm, filler of 147mm, and pico pin of 183mm approx. Similarly die case consists of fillers, die pin of 306mm approx. The pushing rods push these die pin to kick the piece out of the die. The flat of cam brake is made inside the punch and the body and teeth of cam brake are made in die. Total 4 die-punches are used to produce a front
43
cam brake. Punch #2 and punch #3 are filled with spring because flat is made in punch in this case.
sizes of flat according to the sequence Punch #1- 24.30mm Punch #2- 23.20mm Punch #3- 22.40mm Punch #4- 21.60mm
Punch #1- 16.78mm to 16.80mm Punch #2- 17.60mm to 17.70mm Punch #3 –17.95mm to 18.05mm Punch #4- 18.10mm to 18.25mm
sizes of body according to sequence Die #1- 42.0mm Die #2- 47.90mm Die #3- 48.50mm Die #4- 50.00mm to 50.30mm
Fig 3.5.3 Types Of Die Used In Bolt Maker Machine: Bolt former heading die
Hex bolt die
44
Bolt trimming die
Table 3.5.3Specifications Of Cam Brake S. no 1 2 3 4 5 6 7 8 9
Product parameter Total length 2nd length Body length Flat length Flat length Flat dia. Collar dia. Collar thickness Body dia.
Specification 77.00mm 50.20mm/50.60mm 33.50mm/33.89mm 21.50mm/21.70mm 8.05mm/8.25mm 18.05mm/18.25mm 25.00minimum 3.70mm/4.00mm 14.50mm/14.60mm
3.5.4 Instruments And Gauges Used 1. dial gauge 2. teeth alignment gauge 45
3. collar gauge 4. micrometre 5. veneer calliper
3.5.5 Tools Used Regularly 1. 2. 3. 4. 5. 6.
Allen keys files spanners ring spanners blue paste diamond paste
Breakdown
5th August- problem was occurring at punch #1.there was improper extrusion. Corrective action: - toning of punch was filed using diamond paste.
6th August - problem was occurring at punch #3.punch pin was broken. Corrective action: - new punch pin was used.
7th August: - tooling problem. Punch #2 was not holding the piece of punch #1 i.e. punch #2 was undersize and all punch toppings were out in size. Corrective action: - punch #2 was replaced with older punch. Preventive action: - toolings and drawings will be provided with tolerances.
Things To Check Before Starting Of M/C
1. Die and punches should be installed properly and accurately. 46
2. Fillers and pin should be of accurate length as per our requirement. 3. Timing of fingers should be accurate. 4. Timing of kick out should be accurate otherwise it can damage the transfer. 5. Oil should be running properly. 6. Piece should come out properly from the die otherwise while moving of transfer finger and transfer can get damaged. 7. All the bolts and nuts should be properly checked.
Axle Front (Dk-15-1008) An axle is a central shaft for a rotating wheel or gears. Cam brakes are used in motor bikes. axle front is produced from the warm steel wire of dia 17.50.the length of 216mm from the feed is cut at the cut off with the cutter and is made to pass through three diepunch to produce final component as per requirement. Our customer for this product is Bajaj autos, hero moto corp. etc.
Procedure Of Axle Front for the production of cam front brake the raw material of dia 17.50 is taken from wire stand and with the help of feed it is send into the m/c where it comes upto quill. Quill helps to keep the wire straight and it carries the wire upto the stopper. Stopper is set according to the requirement. When piece comes upto the stopper, cutter cuts the wire as per the requirement and then finger collects it from there and takes it to die #1 and holds it till the punch #1 comes and pushes the wire into die. When the piece gets inside the die then with the help of kick out and pushing rods the piece comes out of the die and then finger collects it from there and take it to die #2 and holds it there till the punch #2 comes and punches the piece into die #2 and then same procedure continues till the piece passes through die # 3 and then pushing rod pushes the piece out of the die and with the help of conveyer piece is collected in the bin kept under the conveyer blet. Die And Punches
47
dies and punches used for the production of front axle is made of carbide material.the die is put into the die case and the punch is put into the punch case.all the punches and dies are put into die and punch block respectively.punch case consists of punch pin,fillers and picopin.similarly die case consists of fillers,diepin.the pushing rods push these die pin to kick the piece out of the die. the dies and punch are solid from inside because whole component is made in die in this case.
size of head according to the sequence punch #1 :- 64.00mm Punch #2:- 61.00mm Punch #3:- 50.00mmsize of body according to the sequence Punch #1:- 60.00mm Punch #2:- 191.00mm Punch #3:- 170.20mm to 170.40mm
Table 3.5.5 Specifications Of Front Axle S.no
Product parameter
Prod/process/specification
1 2 3 4 5 6 7
Head length Body length Trod length Trod dia. Head dia. Body dia. Total length
50mm 170.20mm to 170.40mm 27.3mm 12.85mm to 12.89mm 21.00mm to 21.50mm 15.02mm to 15.10mm 248.70mm
Instruments
48
1. veneer calliper 2. micrometre
Tools Used Regularly 1. 2. 3. 4. 5.
Allen keys Spanner Ring spanner Files Diamond paste
Breakdown
9th September: - finger timing was out and die pin was broken. Corrective action: - finger timing was changed and new die pin was used. 10th September: - improper extrusion .t.r.d length was not coming as per requirement. Corrective action: - tired die was faced and timing of kick out was changed. Result
Precision Cold Forging technology and processes for producing near-net shape or netshape engineering component are critical for the precision engineering industry to remain competitive in the global market place. The technological data and know-how for utilising the three innovative processing techniques and the hydro-pneumatic pressure control system obtained in this project will be useful for future in-house and industrial projects. A large industrial project with Microturner is on- going in the cold forging of components. The capability of cold forging process to manufacture small netshape parts with critical dimensions can be achieved. Parts can be produced with reduced processing steps and eliminating secondary processes such as machining operations. As Microturner strives to become a knowledge based economy, innovative metal processing techniques as mentioned will spark the interest for the industry to meet the technological challenges ahead. At present, the information with regard to tool design, process design and process signature are continually being utilised in carrying out the existing industrial projects. In 49
the pipeline, discussion is in- progress with other local large companies and MNC’s in Cold forging of precision components. The completed research project will be a good foundational platform to manufacture high precision and high value-added components to maintain a strong competitiveness environment in Microturner.
Conclusion As an undergraduate of the Bahra University I would like to say that this training program is an excellent opportunity for us to get to the ground level and experience the grateful to the Bahra University for giving me this wonderful opportunity. The main objective of the industrial training is to provide an opportunity to undergraduates to identify, observe and practice how engineering is applicable in the real industry. It is not only to get experience on technical practices but also to observe management practices and to interact with fellow workers. I is easy to work with sophisticated machines, but no with people. The only chance that an undergraduate has to have this experience is the industrial training period. I feel I got the maximum out of that experience. Also I learnt the way of work in an organisation, the importance of being punctual, the importance of maximum commitment, and the importance of team spirit.
50
The training program having three destinations was a lot more useful than saying at one place throughout the whole six months. In my opinion, I have gained lots of knowledge and experience needed to be successful in a great engineering challenge, as in my opinion, Engineering is after all a Challenge, and not a job.
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