Rectangular embossing

In order to calculate the punch force and the reduction in sheet thickness for rectangular hollow stampings, these must be divided into different sections. A rectangular hollow embossing is made up of the straight sides and the four corner areas, which together form a rotationally symmetrical hollow embossing.

It is assumed that the linear decrease in sheet thickness is the same over the entire circumference of the embossing. The minimal thickness determined for the corner areas is also assumed for the straight sides. This assumption is only valid if the flow of material on the straight sides is inhibited in a comparable way to that in the corner areas.

After the stamp force for rotary hollow embossing has been determined, it can easily be scaled with the circumference of the rectangular stamp to calculate the stamp force for rectangular embossing.14