Roll forming is a process in which the sheet is deformed in the required shape by passing the plain sheet through the progressive dies (i.e. rollers) in which the angle changes simultaneously to the desired form. The picture on the bottom left shows three set of dies, the first pair is the flat die at 180o angle. The second pair is inclined at 157.5o and the third to 135o. On the bottom right shows the sheet under deformation which shows the three deformed regions under the three pair of dies. On the top is shown the simulation of roll forming.