The female die, also known as the female die, is a part of the outer surface of plastic parts. In injection molding, it is usually installed on the fixed plate of injection molding machine, so it is customarily called fixed mold. It is the most difficult part to process in injection mold. According to their different structures, there are mainly the following types. (1) Integral female die This type of female die is directly processed from a whole piece of metal material, as shown in figure 1. It has simple structure, high strength and good rigidity, and there will be no traces of flat seams on plastic parts, so it is generally not heat treated. Suitable for small and medium-sized plastic parts with simple shape. Figure 1- Integral concave and convex (2) Embedded concave die This type of concave die is evolved from the integral concave die. It embeds the female die directly into the fixed template or die set, and then embeds the die set into the fixed template. Because the cavity of the female die can be processed independently,