Brief Introduction on Tungsten Carbide Cold Heading Dies

1. What is tungsten carbide heading die?

With high hardness and high bending strength, the tungsten carbide cold heading die is pressed and sintered by powder metallurgy. It is widely used in molding and fastener-making fields. The tungsten carbide heading die blanks are used as the core insert to be pressed in a steel jacket. Combined with a steel jacket, the cold heading die is more wear-resistant and more efficient, and the service life is increased a lot.

2. Working conditions

Under strong impact force, the impact pressure stress of the punch can reach more than 2500MPa, the surface of the concave die and the working surface of the punch are both subjected to severe impact friction, and the temperature generated on the surface is as high as 300℃. Due to the unequal end faces of the blank, the punch will also be subjected to bending stress. Cold heading dies under impact or strong impact wear-resistant working conditions, their commonality is that the cemented carbide has good impact toughness, fracture toughness, fatigue strength, bending strength, and good wear resistance. So many fasteners are formed by cold heading dies.

3. The main failure modes

Excessive wear on the working surface of the convex and concave die, occlusal damage, local groove peeling, upsetting or breaking of the punch, swelling or cracking of the die, collapse of edges and corners, etc.

4. Performance requirements

The cold heading die bears the impact load generated by the heading, and the working surface of the die is required to have high hardness and wear resistance, and the core has sufficient strength and toughness. If the hardened layer of the cold heading die is too hard or too deep, the mold parts will be broken; on the contrary, the working surface of the mold parts is easy to wear, and the rough material adheres to the mold parts. Usually, the hardness of the punch is 60~62HRC, the die is 58~60HRC, and the depth of the hardened layer should be controlled by 1.5~4mm. The cold heading die is subjected to severe stamping loads, and the surface of the die is subjected to high compressive stress. The mold material is required to have high strength, toughness, and wear resistance.

Zhuzhou Better Tungsten Carbide Company has been producing tungsten carbide dies for over 15 years. We have thousands of sets of mold to produce different carbide heading dies.