Differences between cold metal stamping and hot metal stamping

Metal stamping or stamping is the manufacturing technique used for the transformation of metal sheet, where the piece is subjected to a compression load between two moulds. This load is applied through hydraulic or mechanical presses that provide a great capacity and versatility to apply the most efficient and productive processes depending on the requirements of each project.

There are two types of stampings, cold stamping and hot stamping, depending on the temperature applied to the material to be deformed.

DIFFERENCES BETWEEN HOT AND COLD STAMPING

The temperature applied in the deformation of the metal is the key factor that differentiates the technique of metal stamping in cold and hot. This line separating both processes is determined by the recrystallization temperature. If the temperature applied is higher than this, it is hot stamping, while if it is lower, the process is called cold stamping.

The recrystallization temperature is the temperature by which a cold-worked material is recrystallized, i.e., as with all deformed material, a microstructure is formed of new grains that have few dislocations in their crystalline structure. This factor depends on the melting temperature of the metal, as well as the degree of cold deformation, among others. Therefore, it is not a fixed temperature.

HOT METAL STAMPING

Hot stamping of metals is carried out at a temperature higher than the metal recrystallization temperature. This technique involves heating the material until it becomes malleable to form the required part.

Unlike cold metal stamping, the resulting part has less dimensional accuracy, although it allows more deformation of the part thanks to its high temperature.

COLD STAMPING

In cold metal stamping, the material is produced at a temperature lower than the recrystallization temperature. In this process, the deformation of the grain of the crystalline structure makes it possible to obtain anisotropy in the microscopic structure. Thus, properties such as the elasticity or ductility of the metal undergo alterations that make it possible to manufacture more resistant materials, as well as solutions for reducing the weight of the final piece.

At SOME, we are specialists in cold stamping processes. The main techniques we develop are:

• Deep and semi deep drawing
• Stamping with progressive dies

These metal stamping operations are aimed at projects that require high productivity in medium or long series.

For this purpose, at SOME we have a wide range of mechanical presses of up to 350 tons to develop the metal stamping process. We also have deep-drawing and semi-deep-drawing hydraulic presses of up to 500 tons.

This machinery allows us to carry out cold stamping operations to manufacture parts and components of different materials, such as steel, stainless steel or aluminium.

If you need more information on cold stamping techniques, please do not hesitate to contact our team.