Mr. Wang, who’s been on my WeChat for many years, asked a question in my livestream: “I have a product made from 45 steel. Currently, I’m using 8566 steel for the punch, which has six sharp corners. The corners keep breaking off—what’s the problem? I only need to stamp about 1,000 products before the corners break off. It’s driving me crazy. The material is 3 mm thick.”
When he asked the question in the livestream, I told him right away: “You’ve definitely fallen into a trap.” 8566 is a crack-resistant steel designed primarily to prevent mold cracking. It won’t cause corner chipping when stamping 3mm-thick 45 steel. Even if there are sharp corners, they won’t chip after just 1,000 stamped parts—let alone make you dizzy. Only Four Copies 8566 would drive you to the point of dizziness.
8566 is a proprietary crack-resistant steel developed by Yuhui Mold Steel, specifically designed to prevent mold cracking. It has accumulated over a thousand case studies across 5 stamping conditions, 6 major material types, and 7 major industries. The crack resistance of 8566 is 4 times that of high-speed steel SKH-9 and 2 times that of D2, with a hardness of 58–60 HRC. It primarily solves cracking issues that high-hardness mold steels such as D2, DC53, and SKH-9 cannot resolve. In particular, 8566 is used to solve chipping problems in stainless steel stamping, sharp-corner stamping, narrow-flange stamping, and thick-sheet stamping—even in narrow-flange conditions where the punch width is less than the sheet thickness and the stamping ratio is less than 1:1.
Due to its high market visibility, strong sales, and customers specifically requesting it, 8566 has attracted widespread imitation across the industry. Not only are there direct copies of 8566, but also “shadow” versions of 8566, and it has even become a reference standard for certain major steel mills. This is an unprecedented and bizarre phenomenon within the industry.
After the live stream ended, he left me a message on WeChat and sent me a photo. His product had six sharp corners, and the corners were quite pointed. However, his material was only 3 mm thick—a relatively thin 45 steel blank that isn’t particularly hard. The 8566 anti-chipping steel shouldn’t have caused the corners to chip so quickly, so I concluded that he had purchased a counterfeit version of 8566.
Moreover, he added me on WeChat back in 2019. I’ve posted over 2,400 videos since then, so he must have watched them and known that 8566 is a Yuhui proprietary product. Yet the 8566 he’s using now causes the tips to chip after just 1,000 stamped parts—a problem so frequent it’s driving him crazy. This is undoubtedly the result of using counterfeit 8566 steel.
Mr. He was precision stamping 7mm 45 steel gears in a single step. The precision stamping die requires a fully polished strip with very small clearances, so the demands on the die steel’s crack resistance are higher than for ordinary stamping. His original punch was made of DC53, which could only produce 2,000–3,000 parts before cracking by 5–6 mm. Later, he switched to LD steel and reduced the hardness, but it could still only produce 5,000 parts, with each fracture resulting in a 2–3 mm break.
After Mr. He contacted me, I recommended he use 8566 anti-fracture steel. Now, with 8566, he can produce 25,000 parts—a service life five times longer than that of LD steel.
Mr. He performs single-step fine blanking of 7mm-thick 45 steel gears; using 8566 chipping-resistant steel, he can achieve 25,000 presses. In contrast, when he stamps 3mm-thick 45 steel, the tip corners crack after just 1,000 presses. When comparing the results, the difference is stark.
When it comes to punch chipping, using 8566 die steel is like night and day—it won’t give you a headache.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.