The factors that determine the performance of die steel are alloy composition, smelting quality, and heat treatment processes. These three elements form a three-legged stool where each supports the others; if any one of them is weak, it will affect the performance of the die steel and its service life.
A netizen asked me what type of die steel is best for stamping 0.3-thick pure titanium without the blade sticking. Currently, they are using DC53 and SKH-9 high-speed steel, but burrs appear after stamping just a few hundred parts. Are there any die steels you would recommend?
Titanium is very ductile, and during punching, it’s prone to “breaking but not severing”—where the material remains connected—which is a major test of the die steel’s metallurgical quality. If your die steel has poor metallurgical quality and contains microscopic cracks invisible to the naked eye, this “breaking but not severing” issue will occur even when punching pure iron.
DC53 has a hardness of 60–62 HRC and excellent wear resistance; it shouldn’t develop burrs from wear after stamping just a few hundred parts. SKH-9 is another tungsten-containing high-speed steel with a hardness of 62–64 HRC, offers even better wear resistance than DC53. However, it still develops burrs after stamping just a few hundred products. This is a form of adhesive wear caused by material adhesion, which is also due to poor smelting quality of the die steel—specifically, segregation and microscopic cracks in the microstructure. When stamping titanium materials, this leads to adhesive wear caused by material adhesion.
Once metal shavings adhere to the die, the material may remain partially attached during punching, resulting in burrs on the product. In such cases, we must select a die steel with superior smelting quality; PM23 powdered high-speed steel is a suitable option.
PM23 has a hardness of HRC 64–66, with fracture resistance and wear resistance 2–3 times that of SKH-9. Crucially, the powder metallurgy process eliminates segregation and fine cracks, preventing material adhesion. When used to stamp pure titanium or nickel-based alloys, it will not stick to the material or produce burrs, and it offers excellent wear resistance and a long service life.
Our client, Mr. He, stamps 1.2-thick nickel-based soft materials, which are quite malleable. When he originally used D2, the die wore down easily and produced burrs. Later, he switched to ASP23, but the die showed signs of wear after stamping just 60,000 products. He then tried ASP60, which had sufficient hardness, but the narrow edge strips were prone to chipping.
After he contacted me, I recommended this powder-metallurged high-speed steel, PM23. Once implemented, the die was able to stamp 100,000 times—significantly better than the original ASP23—and it didn’t suffer from chipping like the ASP60 did, while also being much more affordable than ASP60.
As Mr. He mentioned, when stamping 1.2-thick nickel-based soft materials with products featuring narrow edges, using PM23 not only ensures a service life of 100,000 cycles but also prevents chipping—it offers excellent value for money.
Regarding the netizen’s question about stamping 0.3-thick pure titanium—where DC53 and SKH-9 produce burrs after just a few hundred stamping cycles—this is caused by adhesive wear due to material adhesion. Using PM23 will solve this problem.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.