Molded parts refer to the various parts that make up the shape of a product, including moving molds, fixed molds and cavities, cores, forming rods, and exhaust ports. The molded part consists of a core and a die. The core forms the inner surface of the article and the die forms the outer surface of the article. After mold clamping, the core and cavity form the mold cavity. According to the process and manufacturing requirements, sometimes the core and the die are assembled from several pieces, sometimes made in one piece, and inserts are only used in parts that are easily damaged and difficult to machine.