Mr. Cheng asked if there were any die steels he could recommend that don’t stick to the material and don’t crack.
He’s currently cutting 5mm iron sheets, and using DC53 for the base plate causes sticking, resulting in burrs on the products. Coating doesn’t help either—applying a coating requires polishing the mold first, which is a hassle, and the coating costs are high, running over 800 yuan per mold, yet it still doesn’t completely solve the sticking problem. DC53 is also too brittle; the mold cracked and became scrap after producing 50,000 parts, which is very uneconomical. Therefore, he asked me to recommend a die steel that neither sticks to the material nor cracks.
Iron sheets are very soft, and since they are 5mm thick, they are prone to material sticking and adhesive wear. This is especially true when the die steel has segregation or fine microcracks in its structure. In such cases, the key is to select a die steel with a uniform structure, free of segregation and microcracks, as the base material.
Coating can resolve some mold sticking issues, but in cases where segregation is too severe, the coating cannot fully mask it. He is currently using DC53 for the base mold, and even after coating, it still tends to stick and form stringing. This further confirms that the DC53 he purchased has poor smelting quality, with severe segregation and numerous microcracks.
Of course, DC53 is a high-carbon steel with a carbon content of 1.0%. High-carbon steels are inherently prone to segregation. Coupled with the fact that DC53 prices are falling and smelting quality is deteriorating—with manufacturers cutting corners wherever possible—it’s no surprise that segregation is so severe. This is the downside of low prices. Poor smelting quality leads to poor resistance to chipping and cracking. The fact that his mold cracks after just 50,000 stamping cycles further confirms this.
For this type of thick-sheet stamping, DC53 is prone to mold cracking and also tends to stick to the die and cause wire drawing. I recommend 8566 die steel.
8566 has four times the crack resistance of high-speed steel SKH-9 and twice that of D2, with a hardness of 58–60HRC . It can solve the cracking issues that high-hardness mold steels like D2, DC53, and SKH-9 cannot resolve; This is particularly true in harsh conditions such as stainless steel stamping, thick-sheet stamping, fine-blanking dies, sharp-corner stamping, narrow-flange stamping, and applications where the punch diameter is smaller than the sheet thickness or the stamping aspect ratio is less than 1:1. Cracking issues that standard die steels cannot resolve are all effectively addressed using 8566 anti-cracking steel.
Mr. Zhao is precision stamping 6mm-thick Q235 steel, which requires a bright finish on the outer diameter. Due to the tight die clearance, he has tried both DC53 and SKD11, but neither has yielded satisfactory results—primarily because the cutting edges crack, typically by about 1 cm each time. With softer sheet metal, he can produce over a thousand parts, but this requires constant die trimming, and the finished parts still fail to meet precision requirements.
Precision stamping dies require a fully bright edge, and the die must not stick to the material. If material adheres, the product will develop stringing, defeating the purpose of achieving a fully bright edge. The material must also maintain high toughness and high wear resistance. The fact that Mr. Zhao experienced chipping with both SKD11 and DC53 indicates that these materials are unsuitable for thick-gauge stamping—they are too brittle and prone to cracking.
However, after Mr. Zhao switched to 8566 anti-cracking steel for his dies, he produced 250,000 parts without a single instance of chipping. This clearly demonstrates that 8566 offers excellent resistance to cracking, does not stick to the material, and provides sufficient wear resistance.
Therefore, given that Mr. Cheng is currently stamping 5mm-thick steel sheets—where DC53 tends to stick to the die and cause stringing, and even coatings are ineffective, leading to die failure and scrapping after just 50,000 products—and considering the performance requirements for the die as well as Mr. Zhao’s case experience, I strongly recommend that you use 8566 anti-chipping die steel.
Using 8566 die steel for punch chipping is like night and day compared to the old solution.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.