The cold heading die bears the heavy pressing load, and its female die surface bears high-pressure stress so that the die core material is required to have high strength, toughness and wear resistance, tungsten carbide with high cobalt content(Most grades applied to the heading die core contains cobalt more than 12%, some even reach up to 25%) can perfectly meet this requirement, so all better heading die with long service time use tungsten carbide as die core material, and the outer case of the die is made of hot working die steel (the hardness after heat treatment is about HRC 45). The core is inserted the outer case by cold pressing or hot pressing method, so as to make the core and case combine tightly, and the outer case causes certain compressive stress to the inner core, which improves the service conditions of the die and extends the service time of the die.
Cold heading die(also mentioned as cold header dies) for fastener industry can be divided into cutting die, forming die, and trimming die as per the different production process of a fastener product, and forming die includes the first station, second station, third station, up to the fifth station for some complicated items. Divided by detailed fastener products, there are bolt die, screw die, nut die, hexagon nuts with flange die, drill point die etc. The carbide grade for flanged hexagon nuts is special, please check with Betalent carbide sales person.
In addition to cold upsetting, there is also a warm heading or hot heading process used in fastener manufacturing, especially for large size or complicated deformation fastener blanks, when cold heading may cause heading defects. Betalent has a series of carbide grades for warm heading, hot heading and hot forging, below is the list:
Warm Heading Carbide Grade
Impact force (Kgf-m/cm²)
Warm heading die
For more grades please contact sales person.
1. If you have the experience to use a satisfied carbide material, you can choose a similar hardness carbide grade from Betalent carbide to replace.
2. If there are two or more grades that can meet your needs, you can choose the harder carbide grade for the die core to gain a longer service time.
3. If you want to improve your heading die further or want to change to a better supplier, it is very important to describe the current problem of the current die to Betalent salesperson, and if possible take show the picture of the broken point detail of the die, sometimes a problem may be caused by too hard grade, sometimes too soft, sometimes special formula grades may be needed, you can turn to Betalent carbide’s professional engineer team for a solution.