What is the “Cold forging die”?

It’s used in extremely harsh working environments.
The pressure on the contact surface of the cold forging die will be around 2000 to 3000 MPa.
It is estimated that the very surface temperature of the forged material reaches about 600 ° C or more due to the heat generation based on plastic deformation and friction.

＜Advantages of cold forging dies＞
Despite of its high pressure condition, the cold forging is considered to have little effect on the deterioration of tool life since the processing temperature is below the tempering temperature of steel.

＜Disadvantage of cold forging dies＞
The poor surface condition directly affect seizure and wear, which make the forging die unusable immediately.

What are the differences between hot, warm and cold forgings?

In hot forging and warm forging, the material is heated above or near the recrystallization temperature to make it soft and to avoid the fracture under excessive deforming condition. The improvement of material properties can be achieved by forming under compressive stress status. However, the quality of hot forged product, such as dimensional accuracy and surface quality, is usually worse comparing with cold forging.
On the other hand, cold forging performs at room temperature. The advantage is that the product having high-strength, high-dimensional accuracy, and high-surface quality can be manufactured with high productivity. The disadvantage is that high tool loading condition and severe material deformation may lead to problems such as tool failure during forging and dimensional changes due to residual stress.

General features of cold forged products

Since the effect of temperature is small, it is possible to predict the deflection behavior of the dies with some accuracy. By using the predicted deflection amount in dimensional modification of dies, highly accurate forging products can be produced.
In addition, the surface quality (such as surface roughness) of forged product can be improved since the fine finishing status of die surface is transferred to the forged product due to high pressure applied on the contact surface.

Features of cold forging dies made by YEG

With over 50 years of experience and know-how, and the latest simulation technology, we provide the forging dies with the highest quality. In particular, we are working to further enhance our skills and technology while quantifying and sharing the advanced technology called "takumi" that was thought to be possible only by human hands.