Progressive stamping is a metalworking method that can encompass punching, coining, bending and several other ways of modifying metal raw material, combined with an automatic feeding system. The feeding system pushes a strip of metal (as it unrolls from a coil) through all of the stations of a progressive stamping die. Each station performs one or more operations until a finished part is made. The final station is a cutoff operation, which separates the finished part from the carrying web. The carrying web, along with metal that is punched away in previous operations, is treated as scrap metal. Both are cut away, knocked down (or out of the dies) and then ejected from the die set, and in mass production are often transferred to scrap bins via underground scrap material conveyor belts.
Progressive molding is a metal forming process widely used to produce parts for various industries, such as automotive, electronics and appliances. Progressive molding consists of several individual work stations, each of which performs one or more different operations on the part. The part is carried from station to station by the stock strip and is cut out of the strip in the final operation. The decision to produce a part in progressive die or transfer die is dependent on size, complexity and volume of production. Progressive molding is used to produce a large number of parts and keep the costs as low as possible. The highest demands in precision and durability must be met. Due to the complexity of progressive dies, it is important to address all the factors that contribute to achieving the desired level of part quality, including blank position, pilots, blank boundary and stretch-web deformation. Pilots play an important role in progressive die stamping – they fix the strip into an appropriate position and maintain control over it. In addition, they are essential for precise sheet positioning during tool closing and drawing operations in transfer dies. Other factors to be considered are timing and interaction of carriers, pads, and upper and lower tools. The benefits of progressive die stamping are increased productivity and significant cost reduction for high-volume production.