 Hello friends, I am Mr. P. P. Mitragutri, Associate Professor in Department of Mechanical Engineering at Valchand Institute of Technology, Solapur. Today we are going to discuss regarding types of press working dyes. Now learning outcome for this particular session is students will be able to select a proper press tool for manufacture of sheet metal component at least possible cost. Now before understanding what are press working dyes, first of all let us understand what is a press working and what is its significance. Now press working is a cheap less manufacturing process by which various components are made from sheet metals. It involves working of a sheet between two dyes. In press working the upper die is called a punch and the process is termed as cold stamping. Before going to the next slide I want to tell you the significance of press working. Now this press working with sheet metal is very significant as far as automotive industry is considered. Friends you may not imagine there are more than 200 press components which are used in a car and there are more than 40 to 50 components made from by press working which are used in two wheelers and three wheelers. So you will find press working as essential part of automotive industry. It is essential need of automotive industry. Now next we will study what are the press working dyes. Before that we will study what is die. The die is defined as the female part of a complete press tool for producing the work in a press. It is also referred to a complete tool consists of pair of meeting members for producing work in a press. Now classification of dies is the next portion in that we can classify the dies in two ways depending upon according to the type of press operation that is cutting dies and forming dies. Cutting dies are the dies which are used for cutting operations. Cutting operation means piercing a hole, cutting a blank, slitting, lensing these are some of the cutting operations which are carried out with cutting dies. Cutting dies are used to carry out stretch forming, cup drawing and some other related bending dies are also referred as forming dies. Second way of classifying the dies is according to the method of operation. Now this can be classified into seven different ways that is simple dies or single operation dies, compound dies, combination dies, gang dies, gang and follow dies, progressive dies and transfer dies. Now in the next slide we will discuss every type of die set, its application, its limitations. Now simple dies or single operation dies are as shown in the sketch. These are single action dies. They produce one component per stroke. These single operation dies or simple dies can perform cutting operation or may be employed for forming operation. Simple dies require a press operator to load and unload the component that is loading and unloading of the component in case of simple dies is manually done and part material is to be manually placed and after each press cycle part material is to be withdrawn. It means that the time required for production of the component on simple dies is much greater. Time consumed for particular operation is greater and single operation die or simple dies are generally used only when blanking or piercing operation is to be done or only some bending operation or something is to be done and these dies are used for simple shapes. Now some simple shapes which are formed by use of simple dies are shown in this slide. You can observe various contoured parts can be produced with the help of simple dies. Now if you have a component to be manufactured as shown in the sketch in the slide that is parts produced by compound die you can find that it involves two operations. Every component involves two operations blanking and piercing and these two operations can be performed with simple dies by using two simple or single cutting dies. But instead of that if you want to perform both the operations simultaneously instead of simple dies you can go for compound dies. In compound dies you can observe that two or more operations may be performed at one station. It is specifically employed for cutting operation only and as both the operations are taking place in single setting accuracy and concentricity maintained and tolerances maintained will be better and production of component will be definitely economical and fast as compared to using two simple dies. But compound dies no doubt initial cost are high and they are complex in nature. Now next type of die where we can manufacture we can perform two or more operations is combination dies. But combination dies differ from compound dies in a way that in compound dies you can perform both cutting operations. But in combination dies one cutting operation and another forming operation if it is to be carried out you can go for combination dies it differs from compound dies in that respect and in this case presses required are double acting while in case of compound dies single acting press can be employed while during forming operation the first blank which is cut and then blanking punch acts as a punch holder and this is very costly and the blank cut and shell drawn is shown blank is cut in the first operation and shell is drawn in the second operation. Now next type of die is gang dies. Now you look to the component shown at the bottom in the sketch you find that there are more than two or three piercing operations in a blank rectangular blank. If you want to perform this at one stroke you have to go for gang dies gang die is nothing but a single operation die or you can say that modification of a simple die only thing is that to the punch head we will have to mount more than one punches and die block will have more than one die cavity and gang die will look as shown in the sketch it is employed for cutting operation only. Now all the punches are operating simultaneously gang dies as a result of which force requirements are normally very high that is the trouble now I will pose one question before you that is how we can reduce the force requirements in case of gang dies you think over it and you try to find out the answer for that. Now one solution I will give for that is gang and follow dies gang and follow dies is nothing but modification of a gang dies only thing is that number of punch in case of gang and follow dies also number of punches are mounted but all punches are staggered as a result of which every punch will operate after first punch has completed its operation second punch will start operating and after second punch operates operation is complete third punch will begin its operation and last punch will begin its operation after third punch finishes its operation as a result of which force requirements are considerably reduced as compared to the gang dies. Now four most important dies which are used for mass production is a progressive dies the name itself suggests that progressive dies are multi-station dies it performs number of operations at two or more stations during each stroke it can perform very complex work it is used for larger run of production both coiled and strip stock can be used for it stock is automatically located during the operation so accuracy of operation is very good and generally single pass layout is preferred and progressive die is as shown in the sketch now last die is transfer dies these are also multi-station dies but they differ from progressive dies is that already cut blank is transferred mechanically from one station to other station in multi-station dies and several dies are mounted in case of transfer dies set in line or in a circle now at the end of this session we will study comparison between progressive dies and transfer dies no doubt both are multi-station operation dies but progressive die uses continuous strip or stock while previously cut blank is fed to the transfer dies progressive dies can be run at higher speeds with shorter pre strokes and scrap loss in completely low in case of transfer dies but transfer mechanism has higher initial cost in case of transfer dies now at the end of this session I will ask you to refer a textbook of production engineering by PC Sharma tool designed by Donaldson press tool designed by IGTR Aurangabad thank you