Usually, the auto sheet metal prototyping will come into the next process after the blanking completed. Different parts need come into the corresponding process according to the processing request. There are bending, pressure riveting, flanging tapping, spot welding, convex, paragraph difference etc. Sometimes, it need press the nut or stud well after one or two bending. For some moulds, the convex hood and the gap the central need be machined first, in case the intervention if other processes will be processed first, and result in it can not complete the needed processing. When there is a hook on the cover or the lower shell, it can not be welded before bending.