1. Concept of stamping

Stamping refers to a pressurised processing method that uses a mold installed on a stamping equipment (mainly a press) to apply pressure to the material, causing it to separate or plasticize, thereby obtaining the required parts (commonly known as stamping parts or punching parts). It is one of the basic methods of plastic processing.

Stamping is usually cold deformation processing of sheet metal at room temperature, so it is also called cold stamping or sheet metal stamping. Stamping is one of the efficient and advanced metal processing methods in modern manufacturing. The stamping process is shown in Figure 12. The stamping process is inseparable from the stamping die, stamping equipment, and stamping materials.They are the three elements of stamping.

  • The characteristics of stamping and forming Compared with other processing methods (such as cutting and machining), stamping and forming have many unique advantages, in terms of both technology and economy. Its main advantages are manifested in: 1) Stamping products generally do not need to be heated and formed, and this saves energy; less waste is generated during the process, and therefore material utilization rate can reach 70%-85%. Also, the mass production cost is low with promising economic benefits.
  • 2) Stamping can process thin-walled parts with a larger size range and more complex shapes.
  • 3) During the forming process of stamping parts, the material under the action of the mold produces plastic deformation, which improves the internal structure and the mechanical properties of the material, so that the strength and stiffness of the stamping parts are improved.
  • 4) The size and shape accuracy of the stamped parts are guaranteed by the mold. Their quality is stable, interchangeable, and they have the characteristics of “exactly the same”. Under normal circumstances, they can fulfill the functional requirements and assembly requirements.
  • 5) Stamping relies on dies and stamping equipment to complete the process. It can produce dozens or even hundreds of products per minute. The production is efficient and easy to realize mechanization and automation.
  • At the same time, the production process is simple to operate and has low technical requirements for workers.
  • The main disadvantages of stamping processing are manifested in: 1) High precision requirements of stamping molds, complex manufacturing processes, long cycles, and high costs. It is generally produced in a piece-by-piece manner.
  • 2) Stamping processing usually adopts manual operation, which results in high labor intensity and poor safety.
  • 3) There is a lot of noise and vibration during stamping processing. The production environment is poor.
  • 3. Application of stamping processing Stamping processing is widely used in modern industrial production, especially in mass production. According to statistics, in the production of machinery and civilian products such as automobiles, electric motors, electrical appliances, instrumentation, toy manufacturing…etc., stamping parts accounts for 70% to 80% of the total number of parts; the stamping parts in the household appliance industry accounts for more than 85% of the total number of parts; the stamping parts in electronic products such as televisions and video cameras accounts for more than 90% of the total number of parts.
  • Many parts that used to be manufactured by forging, casting and cutting methods are now mostly replaced by stamping parts with high quality and good stiffness. In the composition of steel products in developed countries, steel strips and steel plates account for 67%, which proves from another aspect that stamping has become an important method of modern industrial production and the direction of technological development.