Deep-drawing is a part of Sheet metal processing and the most important forming method for the production of sheet metal parts. According to the definition of DIN 8584, it is tensile compressive forming and the processing is carried out by simultaneous tensile and compressive stress in different operating directions. The drawing method most commonly used is deep-drawing with rigid tools from tool making. The tools consist of a punch, a die and a sheet holder. The sheet metal blank is fixed by the sheet holder and during immersion the stamp spans the sheet in the board across the die radius, pressing it into the die (also called drawing ring). In doing so, the required punch force constantly increases until the dead-centre position is reached. The edges of the punch and the die are rounded, otherwise the sheet might tear. If the roundings are too large, the sheet at the end of the draw can no longer be fixed by the downholder, which may lead to wrinkling. If the draw depth is not reached in a single step, the draw is executed in several steps, especially in case of thick sheet metals.
