How to Choose Between Cold Stamping and Hot Forming

In the area of metal stamping, hot forming and cold stamping are two of main forming processes, with different applications. They have significant differences in equipment configuration, material compatibility, process flow, forming performance, and typical applications. We will explore their characteristics below to help you choose between these two different stamping production lines.

1. Processing Principle

Cold stamping is carried out at room temperature, relying solely on the pressure of the stamping press to shape the material. The thicker and harder the material, the greater the required pressure. Hot forming requires heating the material to a certain temperature before performing the stamping and forming. Heating the material reduces the working load on the stamping press to a certain extent and also enhances its processing capability.

2. Material Processing

One of the main characteristics of high-strength metal sheets in stamping is their high yield strength. Yield strength represents the critical point at which the material begins to deform under force. The higher the yield strength, the greater the required stamping pressure.

Sheets with ordinary strength can usually be processed using cold stamping, but high-strength sheets may be difficult to form, potentially resulting in springback, cracking, or failure to meet the desired specifications. By heating the material to a high temperature, its yield strength is reduced, allowing hot forming to effectively stamp and shape high-strength thick sheets. Although hot forming can also process ordinary-strength sheets, the heating process requires additional time, making its production speed lower than that of cold stamping; therefore, it is generally not chosen for such materials.

3. Processing Characteristics



3.1. Speed

Cold stamping has relatively simple processing steps and allows for high-speed production. Since heating the material requires waiting time, the production speed of hot forming is slower than that of cold stamping.

3.2. Precision

Cold stamping is performed at room temperature, and the finished product's precision mainly depends on the mold, press, and feeding accuracy. In hot forming, if the heating is uneven, the product precision may be lower than that of cold stamping. Additionally, after stamping, the product undergoes a cooling period, during which precision can be affected by thermal expansion and contraction. However, thanks to the improved material flow from heating, hot forming can effectively shape products with complex structures.

3.3. Strength

Cold-stamped sheets generally have ordinary material strength, and the finished product strength is also moderate. Hot-formed sheets have high material strength, and the finished products often exhibit high strength. If needed, the stamping press can also be equipped with water-cooling for quenching, further increasing the strength.

4. Application Scenarios

Cold stamping production lines are widely used across various industries and can effectively produce most products except for high-strength workpieces. Hot forming production lines are specifically used for producing high-strength workpieces in the automotive industry. When producing other types of workpieces, their efficiency is lower than that of cold stamping.