Although 8566 anti-cracking steel is expensive, there are some operating conditions where you have no choice but to use it. Mr. Deng contacted me for advice. He is stamping 4.5mm-thick 40Cr hot-rolled sheet with a material hardness of 26 HRC. Currently, he is using DC53 die steel for the cutting edges, but after 6,000–7,000 stamping cycles, the edges lose their sharpness and the products develop burrs. He asked me what die steel to use for stamping 4.5mm-thick 40Cr that would ensure a long mold life, as he is currently unable to meet production targets.
Stamping 4.5 mm thick 40Cr involves thick, hard material. The fact that the DC53 die produces burrs and loses its sharpness after just 6,000–7,000 stamping cycles is abnormal. Since DC53 has a hardness of 60–62 HRC and excellent wear resistance, it shouldn’t develop burrs this quickly.
Looking at the product, the burrs are all perfectly uniform—tall, dense, and evenly distributed—indicating that the die is experiencing adhesive wear caused by material sticking.
At the locations where burrs appear, there are also small chips on the cutting edge. This further confirms that the quality of the current DC53 steel is very poor; not only is there adhesive wear from material sticking, but chipping has also occurred.
You should select a mold steel that offers better resistance to chipping and material adhesion than the current DC53. Considering the operating conditions, material being processed, and failure mode, I recommend 8566 anti-chipping steel. As a viewer mentioned during my 300th livestream, 8566 is unbeatable for stamping thick plates.
8566 is a proprietary anti-chipping mold steel developed by Yuhui Mold Steel, designed primarily to address mold chipping. Its resistance to chipping is four times that of SKH-9 high-speed steel and twice that of D2, with a hardness of 58–60 HRC. It specifically addresses chipping issues that high-hardness mold steels such as D2, DC53, and SKH-9 are unable to resolve.
8566 has accumulated over a thousand case studies across 5 stamping operating conditions, 6 major material types, and 7 key industries; In particular, in demanding conditions such as stainless steel stamping, sharp-corner stamping, narrow-edge stamping, and thick-sheet stamping—including cases where the punch width is less than the sheet thickness, the punch hole diameter is less than the sheet thickness, or the stamping ratio is less than 1:1—cracking issues that conventional die steels cannot resolve have all been successfully addressed using 8566.
We had a customer who was stamping 4mm-thick 50 steel—a very hard material. His product featured a structure resembling a swallow’s wings, with narrow extensions flaring out on both sides. The punch was only 4mm wide, with a thickness equal to the sheet thickness, and a stamping ratio of 1:1. Given the combination of thick sheet, hard material, and a narrow-edge design with a 1:1 stamping ratio, the punch was prone to chipping. When he used DC53, the punch would shatter after just 10,000 stamping cycles.
Later, Mr. He told me: After switching to 8566 anti-chipping steel for the die, he was able to stamp 32,000 products in a single run—a threefold increase in die life compared to his previous 10,000 cycles.
Mr. He’s die—which involves thick sheet metal, sharp corners, and narrow edges—operates under even harsher conditions. While DC53 was prone to chipping in such conditions, switching to 8566 die steel tripled the punch’s service life. This 32,000-cycle lifespan is 4–5 times longer than Mr. Deng’s 6,000–7,000 cycles. Only when die life is increased by 4–5 times can your stamping process run smoothly. As long as you can produce the parts, even the most expensive die steel has a low actual cost of use. If your die steel is subpar and has a short lifespan, you won’t be able to produce the parts—and even the cheapest die steel will end up being expensive. Therefore, given Mr. Deng’s die operating conditions, he should definitely use 8566 anti-chipping die steel.
Using 8566 die steel to prevent punch chipping makes all the difference—it’s like night and day.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.