Mr. Yuan wanted to purchase 8566 die steel, but after discussing the matter in detail, I advised him against it because the operating conditions of his die were not suitable for this material.
He is stamping 0.5mm-thick silicon steel sheets and described the process as high-speed stamping—3 strokes per second. He is currently using SKH-9, which performed well initially, but after a few hours, significant burrs began to form.
Under these operating conditions, the priority is to improve wear resistance rather than crack resistance. Therefore, he should not select 8566 crack-resistant steel for the die, but rather PM23 powdered high-speed steel.
I have a customer who praised the Yuhui PM23 for being truly effective when making fine punches with sharp corners. Previously, when I used YG15 for punches, they would either chip at the corners or break completely. I punch 0.5mm silicon steel sheets at 250 strokes per minute. Now that I’m using the PM23, I’ve reached 3 million strokes with no wear—it’s fantastic.
My client’s operating conditions are similar to Mr. Yuan’s—both involve punching 0.5 mm silicon steel sheets. My client’s punching speed is even faster, yet using Yuhui PM23, they’ve achieved 3 million punches without any wear. This concrete case study serves as a solid basis for your material selection.
Although PM23 and SKH-9 are both high-speed steels with similar hardness levels, PM23 has a higher carbon (C) content and total alloy content than SKH-9. After heat treatment, it develops a denser structure of hard carbides. Crucially, the advanced powder metallurgy process results in finer, more uniformly distributed carbides, giving PM23 superior wear resistance and better resistance to chipping compared to SKH-9.
The operating conditions of the die determine the material used. Mr. Yuan, you are stamping 0.5 mm thick silicon steel sheets. With SKH-9, significant burrs form after just a few hours of stamping. I recommend using PM23 powdered high-speed steel rather than 8566 anti-chipping steel.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.