Stretching dies, also known as stretching molds, are tools used for bulk processing materials (metals or non-metals) into the required stamping parts. According to their combinations, stretching dies can be classified into single-stroke deep drawing dies, compound dies, and progressive deep drawing dies. When differentiated by stamping equipment, they can also be categorized as single-motion press stretching dies, double-motion press stretching dies, and triple-motion press stretching dies. The main distinguishing factor among these three types is the difference in the design and positioning of the flanging device (elastic flanging and rigid flanging). Stretching dies can also be divided into first draw dies and subsequent process drawing dies, with the primary distinction lying in the structure and positioning of the flanging rings.