For big bolt,screw or nuts, of which diameter is bigger than 30mm, let’s say from 30mm to 80mm, the hot heading produce process is applied. We need to heat the steels to a red hot, then head in hot heading machine to get the hexagon or other shape head. In this process,the carbide heading die is required to have very high heat resistance, Betalent carbide has a special grade for hot heading. That is the BH35, below is the carbide grade physical character chart.
Grade | Co% | Grain Size(um) | Density (g/cm) | Hardness(HRA) | TRS N/mm2 | Impact force (Kgf-m/cm²) | Application |
BH35 | 23 | 2-6 | 13.2 | 83.8 | 2550 | 0.92 | Hot heading |
We did the tool service time compare testing, when the common hot heading grades we can find in the market can produce 10,000 pcs 35mm diameter bolt in average, the BH35 can produce 20,000pcs, which is to say, our grade BH35 can last much longer in hot heading dies application.