The main factors that make mold manufacturing more difficult to process compared with general machinery manufacturing are as follows:

(1) Higher hardness of mold materials:

Molds are a kind of molding processing tool, so the hardness requirements for mold materials are higher than that of parts. For example, the forming parts of cold stamping dies are generally made of quenched tool steel or cemented carbide and other materials. Therefore, it is relatively difficult to manufacture by traditional cutting processing methods.

(2) High requirements for mold processing quality:

The processing quality of molds mainly includes the dimensional accuracy, shape accuracy, positional accuracy (collectively referred to as processing accuracy), and surface roughness of mold parts. The processing accuracy of molds is determined by the requirements of parts and mold structures. Generally, the accuracy of the working part of a mold is 2 to 4 grades higher than that of parts. The manufacturing tolerance is controlled within ±0.01mm, and in some cases, it is even required to be within the micron range. The surface after mold processing is not allowed to have any defects, and the roughness value Ra of the working surface is less than 0.8 μm.

(3) Complex shape and structure:

Most of the shapes of the working parts of molds are complex two-dimensional and three-dimensional curved surfaces, especially irregular cavities. Generally, cutting processing is suitable for processing simple geometric shapes. Therefore, when used to process complex curved surfaces, the processing difficulty increases and the accuracy is not easy to guarantee.

(4) Single-piece production:

Usually, only 1 to 2 sets of molds are needed to produce a certain kind of part. Even hammer forging dies belong to small batch production. Therefore, molds are generally produced in single pieces and mostly processed by traditional methods. The production cycle is relatively long and the investment cost of equipment and tools is relatively high.