I just received an inquiry from Mr. Chen regarding the stamping of 1.7mm-thick 65Mn hardened steel for C-type retaining rings with a material hardness of 45 HRC. Currently, they are using imported PM23 powdered high-speed steel purchased from a certain online retailer for the lower die cutting edges, but the edges chip after producing only 9,000 pieces. He asked if I could recommend a better material.
Stamping 1.7mm-thick hardened 65Mn steel with a hardness of 45 HRC involves stamping thick, hard material, which places extremely high demands on wear resistance and chipping resistance. However, they are already using PM23 powdered high-speed steel, which costs several hundred yuan per kilogram—a material of very high quality—so it shouldn’t be chipping this quickly.
PM23 is a high-speed steel produced using advanced powder metallurgy processes. It has no segregation or microcracks in its microstructure and a hardness of 64–66 HRC. It combines high hardness with high strength, offering excellent wear resistance and strength. However, it’s now chipping after only 9,000 stamping cycles—and this is happening on the cutting edge of the lower die, which is not prone to chipping, with large chunks breaking off. This has indeed left me somewhat puzzled.
But since they purchased the die steel from a major supplier, we can’t really object. All we can do is advise them to perform a tempering treatment to reduce the hardness to 60–64 HRC and try again.
What surprises me even more is that you bought it from a major supplier—a large company that should have after-sales service and the technical expertise to help you solve the problem. So why are you asking me, a lowly staff member? I really can’t figure that out. Maybe it’s the weekend, and he couldn’t reach anyone else.
After giving him the solution and things had calmed down, I suddenly realized that while the product is important, so is the service. The fact that your customers can reach you at any time is a form of assurance in itself.
As consumers, what we fear most is being ignored when problems arise, or facing endless buck-passing. Taking responsibility is not only a duty but also a form of assurance.
*************
Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.