What is Cold Forging?

Forging is one of the oldest methods in metalworking operations. It is classified into cold forging (a type of cold working or cold forming), warm forging and hot forging (a type of hot working) according to the temperature at which it is performed.In this article, we would like to explore about cold forging.

What is Cold Forging?

Cold forging is a forming process of metals below its recrystallization temperature, and the forging is performed below the recovery temperature.
Cold forging is a closed-die process that deforms the metal. It is done by placing the work piece in-between dies and tools with applying compressive forces at room temperature. The process not only changes the shape but also improves the performance of the forged parts due to the refinement of the grain size.
This process is also known as precision forging with near net shape. Therefore, the final products need little or no final machining after a precision forging.


What are the recrystallization temperature of various metal materials?

ccording to the theory of metallogy, the recrystallization temperature of various metal materials is different. As seen the following table:

Metal The lowest recrystallization temperature (°C)
Iron (Fe) 360~450
Copper (Cu) 200~270
Aluminium (Al) 100~150
Tin (Sn) 0
Lead (Pb) 0
Tungsten (W) 1200

According to the data in the table, Even at room temperature or normal temperature, the forming process of Tin and Lead can not be referred to as cold forging, but hot forging. However, iron, copper, and aluminum forming at room temperature can be called cold forging.

What are the cold forging materials?

Cold forging materials require low deformation resistance and good plasticity at room temperature, such as aluminum and some its alloys, copper and some its alloys, low carbon steel,medium carbon steel and low alloy structural steel.

What are the advantages of cold forging?

Because cold forging takes place without heating the metal beforehand, the process provides many advantages

No. Advantage Description
1 Higher Productivity Conventional processes (such as machining or other fabrication methods) involve multiple processes to finish the part. In contrast, cold forging is typically a single-pass forming process that deforms the material into the desired shape, which is suitable for the production of high volumes of parts.
2 Material Savings Cold forging is developed to minimize waste with the elimination of wasted material, this process makes use of raw material in all its entirety.
Each billet is the exact amount of material needed for the final part, so there is no wastage or loss of material.
3 Cost Reduction Cold forging is more economical than other process, because it’s a net-shape 
and near-net-shape process without much finishing if any at all.
And the dies used in cold forging are last longer than in hotter processes that means fewer replacements.
4 Improvement of Part Integrity and Strength A very important factor of cold forging is to significantly improve the strength and integrity of the final part.
The high compression forces in cold forging process rearrange the grain of the metal to increase in impact strength, yield strength, tensile strength
, and to improve the structural integrity.
5 Enhanced Appearance and   Suface Finishing Cold forging is a precision forming that includes a higher dimensional accuracy, presentable appearance, so it does not require post-processing steps like removing burrs, grooves, striations, or others.
The process is optimal
for excellent surface finishing.
6 Eco-friendly Cold forging is probably the most eco-friendly process of its kind in operation.
Cold forging is the process that uses less material, thus produces less scrap. Compared to other process that use heat, cold forging can decrease energy use.

In short, cold forge is a precision plastic forming technology that has unparalleled advantages, such as good mechanical properties of products, high productivity, high material utilization. It’s especially suitable for mass production and can be used as a final product manufacturing method (net-shape forming).
Of course, cold forging also has its shortcoming, such as high material requirements, not suitable for small amounts of processing and high mold requirements.
Cold forged parts are widely used in electric car,aerospace, machine tool industry and other industries.
U-Need has earned a reputation as a reliable supplier of precision parts for cold forging process, we can help you reduce machining times, waste, and costly production steps. For more information about cold forging parts, contact us or request a quote to get started. Our E-mail address: info@uneedpm.com, and website: www.uneedprecisionmachine.com.