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<\/figure>\n\n\n\nFine-blanking dies require a fully polished surface and very tight clearances, placing extremely high demands on the die steel\u2019s resistance to chipping, wear resistance, and non-stick properties. This is especially true for single-step fine-blanking, where the punch must be forced into the material. Since the punch has sharp corners\u2014where pressure is extremely high\u2014the die is highly prone to chipping. Therefore, resistance to chipping should be the top priority when selecting die steel, followed by high hardness.<\/p>\n\n\n\n
Mr. Zhang is performing single-step fine blanking of 4mm pickled sheet metal, and the product features fine teeth. He is using DC53, SKH9, and SKH51 for the punch\u2014this is an incorrect material selection. DC53, SKH9, and SKH51 are all high-carbon steels and are very brittle. This is especially true for SKH9 and SKH51, these are general-purpose high-speed steels (W6Mo5Cr4V2) with a hardness of 62\u201364 HRC and excellent wear resistance. However, conventionally cast high-speed steels suffer from severe segregation, resulting in a microstructure riddled with microscopic cracks invisible to the naked eye. As high-alloy materials, they are hard but brittle, with insufficient toughness to meet the toughness requirements of fine blanking dies.<\/p>\n\n\n\n
Using PM23 powdered high-speed steel that costs several hundred yuan per kilogram is a waste of money\u2014it reflects a flawed material selection approach, and the outcome is bound to be wrong. If it costs only a few hundred yuan now but breaks after just a few thousand punches, this further confirms that this material choice is unreasonable. For harsh working conditions involving narrow edges and sharp corners like these, you must use 8566 chipping-resistant steel.<\/p>\n\n\n\n 8566 is a proprietary anti-chipping steel from Yuhui Mold Steel. Its resistance to chipping is four times that of SKH-9 high-speed steel and twice that of D2, with a hardness of 58\u201360 HRC. It is primarily designed to address chipping issues that high-hardness mold steels such as D2, DC53, and SKH9 cannot resolve. In particular, for stainless steel stamping, sharp-corner stamping, thick-sheet stamping, fine-blanking dies, narrow-edge stamping, and even single-step fine-blanking where the punch width is less than the sheet thickness\u2014especially when dealing with thick sheets\u2014where conventional die steels fail to prevent chipping, 8566 is the solution.<\/p>\n\n\n\n Mr. He used a fine-blanking machine to perform single-step fine-blanking of a 7mm-thick 45 steel gear ring. When using DC53, the punch corners chipped after only 2,000 shots, with each chip measuring 3\u20135 mm. Repairing the punch required wire cutting off a section before grinding, which was time-consuming and wasteful of the punch. After switching to LD mold steel and reducing the hardness, the punch could still only produce 5,000 parts before the corners began to chip off\u2014each time losing 2\u20133 mm. To repair the punch, a section still had to be cut off first. When they switched to the more ductile W360, the wear resistance proved too poor; the punch wore out before reaching 5,000 parts, failing to achieve the desired precision blanking results.<\/p>\n\n\n\n Mr. He said, \u201cI operate a precision punching machine, and efficiency is what I need. The punches for precision punching machines are all cut using slow-wire EDM, which is very expensive. But if the punch chips and becomes scrap before reaching 5,000 products, I have to stop the machine to wire-cut and grind the punch. Not only can I not afford the punches, but even if I could, this level of inefficiency is simply unacceptable.\u201d After he contacted me and began using 8566 anti-chipping steel, a single punch could produce 25,000 parts without chipping. Compared to his previous best-performing LD punches, which lasted 5,000 cycles, the 8566 steel increased die life by five times.<\/p>\n\n\n\n A fivefold increase in punch life means five fewer punches to machine and five fewer die changes\u2014this is the ideal scenario for improved efficiency and reduced costs, demonstrating the high cost-performance ratio of 8566 anti-chipping steel.<\/p>\n\n\n\n Mr. Zhang performs single-step precision punching of 4-thick pickled sheet metal using SKH9, SKH51, DC53, PM23\u2014but in all four cases, the punches chipped after just a few hundred to a thousand strokes, a problem you\u2019ve been unable to solve. You should follow Mr. He\u2019s example and use 8566 anti-chipping steel.<\/p>\n\n\n\n Mr. He performs single-step fine blanking of 7mm-thick 45 steel gear rings\u2014a material thicker and harder than yours, also featuring sharp corners typical of gear products, with a die structure similar to yours\u2014and achieves 25,000 strokes. You\u2019re precision stamping 4mm pickled sheet metal in a single step\u2014using 8566 will definitely last well beyond 25,000 strokes. To solve your die chipping problem and improve stamping efficiency, you should definitely give 8566 anti-chipping mold steel a try.<\/p>\n\n\n\n![\"\"](\"https:\/\/www.wudejiansteel.com\/wp-content\/uploads\/2026\/09\/8566\u6a21\u5177\u94a2\uff0c\u4e0a\u5e02\u516c\u53f8\u73b0\u6b3e\u91c7\u8d2d-1.jpg\")
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