—- Deep Draw Fundamentals: Part 4

Deep drawn metal stampings have basic dimensional characteristics. The first of these would be in regard to material thickness. The bottom of the shell tends to remain the same thickness as the original starting material since this area is not affected by the draw process. This area does not see a change in temper as well since it is not being worked unless it is being coined or flattened.

The bottom wall will tend to thin from the original thickness due to the stretching of the material. The wall at the top is usually thinner than the original stock due to the effect of the draw process. This area is somewhat hardened as well due to the working of the material.

In order to obtain a uniformed wall, pinching or ironing is performed. This is done by limiting the clearance between the punch and die. This is easily accomplished with non-ferrous material but is likely impossible with stainless steel.