With a clean cloth to clean the surface of the outer covering parts. Inspector need to wear the touch gloves along the longitudinal pressing close to touch on the surface of the stamping, the inspection method depends on the checker's experience. Abrasive grinding if necessary by detection of suspicious areas and verified, but this method is an effective method of quick inspection

Wrinkling is stamping production one of the most important and most difficult problems. Corrugate faults will cause many adverse consequences, will constitute a serious when material. Wrinkling will affect the appearance of the parts surface occurred severe, especially embodied in the coating after severe wrinkling will make the parts can't repair, lead to the parts.

Metal stamping parts machining is a widely used method. In the process of metal stamping, involved in deep drawing, trimming, punching and flanging, such as opening process. Make some problem is very complicated.

Automotive covering parts stamping die industry is the foundation for the development of the automotive industry, in the process of car body design, due to the requirement of the fluid mechanics and aerodynamics, the body outer covering parts geometry has become increasingly complex

Trimming die because of its type surface need to bedding-in as tensile, tensile trimming blade need make three-dimensional model to control, some trimming appearance also need to test on the flanging die, decided to size. So the trimming die manufacturing usually after drawing die and flanging die.