Early this morning, Boss Zhang—whom I hadn’t been in touch with for five years—sent me a message. He’s working with stainless steel, which is prone to chipping at the corners, and asked me to send over a sample to test.
After asking a few questions, I learned that he’s punching 2mm-thick stainless steel with products that have sharp corners. He’d previously used DC53, tried forging Cr12MoV, and also tested SKH-9, but all of them were prone to chipping at the corners—just a tiny bit at the sharp edges. Sometimes the chipping occurs after a few hundred pieces, and other times after a few thousand.
If the punch chips after just a few hundred pieces, and needs repair after a few thousand, it’s a nightmare—production simply can’t continue like this.
Punching 2mm-thick stainless steel involves stamping thick, hard material with sharp corners. The punch has a small contact area, so the requirements for resistance to chipping are extremely high. Conventional high-carbon cold-work tool steel simply can’t handle it—chipping is inevitable. The client is currently using DC53, re-forged Cr12MoV, and SKH-9 high-speed steel, all of which chip after just a few hundred to a few thousand pieces. This indicates that DC53, Cr12MoV, and SKH-9 are fundamentally unsuitable for these operating conditions. Many others have encountered the same problem with punch chipping in the past.
Under these harsh conditions—involving thick plates, hard materials, and sharp corners—only 8566 chipping-resistant steel can be used; otherwise, the punch will wear out to the point of being unusable.
8566 is a proprietary chipping-resistant steel developed by Yuhui Mold Steel, primarily designed to address mold chipping issues; it has accumulated over a thousand successful case studies across five stamping conditions, six major material types, and seven major application areas.
The crack resistance of 8566 die steel is four times that of SKH-9 high-speed steel and twice that of D2. With a hardness of HRC 58–60, it can resolve cracking issues that high-hardness mold steels such as D2, DC53, and SKH-9 cannot address; In particular, under severe conditions—such as stainless steel stamping, thick-gauge sheet metal stamping, fine-blanking dies, sharp-corner stamping, narrow-flange stamping, and stamping where the hole diameter is smaller than the sheet thickness or the stamping ratio is less than 1:1—cracking issues that conventional die steels cannot resolve are all successfully addressed using 8566 anti-cracking steel.
Cracking of sharp-edged punches made of 2.0 stainless steel is a specialty of 8566. One netizen commented directly under my video, saying, “Boss, your die steel is pretty good. I bought 8566 from you to punch 2.5 stainless steel—it’s already reached 100,000 punches and still has no issues.”
When customers are willing to comment under my videos saying it works well, it must be truly effective. They even provided specific operating conditions and stamping life—this is a very candid review and a valuable case study.
So, regarding Mr. Zhang’s inquiry about stamping sharp corners on 2.0 stainless steel: DC53, Cr12MoV, and SKH-9 are all prone to chipping at the corners—they’ll chip after just a few hundred or a few thousand strokes, with small chips forming at the sharp corners. I recommend you use 8566 anti-chipping steel. Using 8566 die steel for punch chipping makes all the difference—it’s like night and day.
Mr. Zhang took my advice and placed an order for 8566 anti-chipping steel.
I’m glad you thought of 8566 anti-chipping steel when the punch started chipping; however, I felt a bit disappointed to learn that you only remembered 8566 after trying three different types of die steel and exhausting yourself in the process. It pains me to see you go through so much trouble. For future molds, especially those operating under harsh conditions, let’s not waste time testing so many different types of mold steel—let’s just go straight to 8566 chipping-resistant steel. It’s simpler, less stressful, and saves effort.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.