 Hello friends, I am P. P. Mitramutri, Associate Professor, Department of Mechanical Engineering at Valchand Institute of Technology, Solapur. In today's session, we are going to study part two of design of a progressive dye for a given component. In earlier session, we have already studied design procedure for a progressive dye for a given component up to strip layout. Learning outcome of this session will be, students will be able to design a proper dye set for a given component. Now, in this case, after strip layout has been decided, next part is a calculation of utilization of strip stock. Now, for calculation of utilization of strip stock, we have to calculate area of the blank to be cut. Now, our component is having size of 80 mm by 80 mm square. So, area of the blank to be cut is 80 into 80 is equal to 6400 square millimeter or millimeter square. Now, area of strip required for one blank is width of the strip is 84 mm. So, 84 into 84 mm will be the area of the strip required for one blank, which comes out to be 7056 square millimeter. So, percentage utilization of the strip is calculated as area of the blank to be cut divided by area of strip required for one blank into 100 that is 6400 divided by 7056 which comes out to be 0.9, 0.9 into 100 is 90 percent. It is a very good utilization, very little scrap loss is there. So, our strip layout is very good. Next thing that we have to calculate is press capacity. For calculation of press capacity, we have to decide certain things that is force required for piercing and blanking operation. For calculation of force required for piercing and blanking operation, perimeter for piercing of two hole plus perimeter of blanking has to be decided. Then it is to be multiplied with sheet thickness and shear stress of our component, shear stress of our sheet. Now, before deciding force required, first of all we will decide perimeter for piercing operation. Now, hole to be pierced, one hole is to be pierced has having diameter equal to 8 mm. So, perimeter for one hole will be pi d that is 25.12 mm into two holes is equal to 50.24 mm. Similarly, perimeter for blanking is our blank is square blank having 80 mm sides. So, 80 plus 80 plus 80 plus 80 is equal to 320 mm. Now, for calculation of press capacity, we are already given with shear stress of our sheet metal is 840 Newton per mm square. Sheet thickness given is 1.2 mm. So, force required can be calculated as perimeter for piercing plus perimeter for blanking that is 50.24 plus 320 into this is into bracket into sheet thickness that is 1.2 into shear stress 840 mm which comes out to be 377.23 kilo Newton per mm square which means approximately 37 tons by considering factor of safety and other thing press of 40 ton capacity which is available at our end has to be selected. Now, before considering further part I will pose a question before you that is will you be able to produce this component using a press of 35 ton capacity please presume that 40 ton capacity press is not available with you. So, think over it now next is calculation of punch and die sizes for piercing. Now, for piercing operation hole is to be pierced. So, punch is going to pierce the hole into the strip. So, our size of the punch has to be equal to size of the hole to be pierced. So, punch is of correct size that is 8.00 mm, but size of the die opening has to be greater than the punch size so that we cannot have ragged edges. So, punch size of die has to be greater by punch size plus 2 into clearance. Now, what is clearance? Clearance is assumed to be 10 percent of sheet thickness. So, clearance on one side is equal to 1.2 into 0.1 that is 0.12 mm. So, therefore, size of die opening will be 8 into 2 into 8 plus 2 into 0.2 that is 8.24 mm is the size of the die. Then calculation of punch and die sizes for blanking so in case of blanking operation die opening size shall be perfectly matching with the size of the blank. Another size of the blank is 80 by 80 mm so size of the die opening shall be square of 80 by 80 while size of the punch has to be smaller than the die opening by amount equal to 2 times clearance. So, size of the punch is given by the formula die opening size minus 2 into clearance now clearance is 10 percent of the sheet thickness as already stated. Therefore, punch size will be a square of 79.76 mm size punch size will be square die opening size will also be square. Now, in a schematic sketch we are showing die and punch sizes for piercing operation. If you look to the sketch properly center distance between the two holes which are pierced is 40 mm inner circle denotes the punch size that is 8.00 mm and outer pink circle denotes die opening size and die opening size has to be always greater than the punch size and it is provided with the clearance allowance so die opening size is 8.24 mm hope you are understanding whatever I have drawn now next is the schematic sketch showing die and punch sizes for blanking operation. Now inner square shows you a punch size of 79.76 square all sides of the punch will have dimension equal to 79.76 mm and pink square will show us die opening size that is it is a square of 80 mm side. Now this is the sketch showing the front view of progressive die set now you can observe here there is a punch holder on punch holder you can observe piercing punch and blanking punch. Now as this is a front view you can observe only one piercing punch because another piercing punch is on the back side of this piercing punch so it is not observable in the front view and distance between center distance between piercing punch and blanking punch has to be equal to pitch up advancement as my strip is advancing from right to left so first of all two piercing operations are taking place then the blank which is having piercing operation will come under blanking die and punch set and will get blanked now you can observe that die block in which there are two openings one for piercing another for blanking and below both the die blocks I have shown the angular clearance so that during punching operation scrap will fall down very easily due to angular clearance given to the die block and our product will fall very easily as because of the angular clearance given to the punching die now next is the schematic sketch showing top view of the progressive die set now in this set also you can observe distress between both die sets and punch set is equal to 82 mm that is pitch up advancement in this case you can observe punch size of 8 mm and die opening size of 8.24 mm and center distance between two punches is equal to 40 mm piercing punches is equal to 40 mm then this will complete our design and for further reading I will ask you to refer a textbook of production engineering by PC Sharma tool designed by Donaldson and prestool designed by Indo-German tool Rome Aurangabad thank you