Shell stretching stamping parts are stamped parts processed using stretching technology. Stretching is the process of pressing a flat metal sheet into a die through the movement of a punch. The application of shell stretching stamping parts is very extensive, such as being used as automotive parts, household products, electronic devices, etc.

Shell stretching stamping parts can stretch sheet metal into cylindrical bottle shaped parts; In the stretching operation, the diameter of the billet is influenced by the circumference of the shell, which in turn is affected by the flowability of the stamped material and the inward flow resistance and edge resistance of the peripheral material; When the resistance experienced by the edge material exceeds its limit, the edge will wrinkle and become unstable.

To avoid wrinkling, it is necessary that the stamping material can flow smoothly between the punch and the edge ring. The two main reasons for tensile fracture are: the ratio of the diameter of the stretched stamping part to the diameter of the billet exceeds the limit value, and the stretching radius is drawn from a flat billet into a shell, and when the shell is stretched into a smaller diameter shell, there is a limit value for the inward flow distance of the material, which is usually referred to as the stretching coefficient.

The ultimate tensile coefficient is influenced by factors such as the flowability of the stamping material, the compressive strength of the material, and the flow resistance caused by compression. Excessive flow resistance causes wrinkling at the edges of the shell, which is the area with the weakest material resistance.