{"id":1453,"date":"2026-08-25T09:26:04","date_gmt":"2026-08-25T09:26:04","guid":{"rendered":"https:\/\/www.wudejiansteel.com\/?p=1453"},"modified":"2026-08-25T09:26:05","modified_gmt":"2026-08-25T09:26:05","slug":"the-service-life-of-the-8566-is-less-than-half-that-of-the-yuhui-8566-6mm-40cr-cold-heading-die-blog-289","status":"publish","type":"post","link":"https:\/\/www.wudejiansteel.com\/?p=1453","title":{"rendered":"The service life of the 8566 is less than half that of the Yuhui 8566; 6mm 40Cr cold heading die.blog\u00a0289"},"content":{"rendered":"\n

Yesterday, Mr. Shi came to Yuhui again to purchase 8566 crack-resistant steel, and he told me: \u201cFor cold heading dies, 6.0 40Cr forming dies are prone to cracking. I\u2019ve tried Cr12MoV, DC53, 8566 from a fourth-hand supplier in Ningbo, and Yuhui\u2019s 8566. After comparing them, your Yuhui 8566 die steel<\/strong> still has the longest service life.\u201d<\/p>\n\n\n\n

 Mr. Shi\u2019s die is used for cold heading 6mm-thick 40Cr material to reduce its thickness. Since 40Cr is an alloy steel with relatively high hardness, the cold heading die must withstand immense forces, requiring the die steel<\/strong> to possess excellent crack resistance. Additionally, because the die features a ramped profile, it demands high wear resistance as well. This is an application that requires both wear resistance and crack resistance simultaneously.<\/p>\n\n\n\n

 For this type of cold heading die, using Cr12MoV with a carbon (C) content of 1.5%\u2014a high-carbon, high-chromium cold work die steel\u2014is too brittle and is definitely the wrong choice; using DC53 with a slightly lower carbon content is somewhat more viable, but under such severe, high-stress conditions, even DC53 cannot withstand the load and is prone to chipping, as his current test results have already confirmed.<\/p>\n\n\n\n

 The \u201cFour-Copy\u201d 8566 purchased in Ningbo is also prone to chipping, which is to be expected. \u201cFour-Copy\u201d 8566 merely copies my product descriptions, advertising slogans, and case studies\u2014but the mold steel<\/strong> grade is inferior to mine. Since they cannot replicate my material composition or heat treatment process, its resistance to chipping is naturally poor, and chipping is inevitable. After conducting verification and comparison, Mr. Shi stated that the \u201cFour-Copy 8566\u201d has a service life less than half that of your Yuhui 8566 anti-cracking steel, which further corroborates this point.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

8566 is a proprietary anti-spalling steel developed by Yuhui Mold Steel, primarily designed to address mold spalling. It is not a national grade but rather our company\u2019s proprietary grade and intellectual property; it is not in the public domain. 8566 anti-spalling steel has been used in over a thousand cases across five stamping operating conditions, six major material types, and seven major industries.<\/p>\n\n\n\n

 However, due to 8566\u2019s high market visibility, strong sales, and customers specifically requesting it, it has attracted widespread \u201cfour-fold copying\u201d by competitors across the internet. Not only are there direct copies of 8566, but also \u201cshadow\u201d versions of 8566; it has even become a reference standard for certain major steel mills\u2014an unprecedented and bizarre phenomenon in the industry.<\/p>\n\n\n\n

 The 8566\u2019s resistance to chipping is four times that of high-speed steel SKH-9 and twice that of D2, with a hardness of HRC 58\u201360. It resolves chipping issues that high-hardness die steels such as D2, DC53, and SKH-9 cannot address; In particular, under harsh conditions\u2014such as stainless steel stamping, thick-plate stamping, cold heading dies, sharp-corner stamping, narrow-flange stamping, and stamping where the hole diameter is smaller than the plate thickness or the stamping ratio is less than 1:1\u2014cracking issues that conventional die steels cannot resolve are all addressed using 8566 anti-cracking steel.<\/p>\n\n\n\n

 I was delighted to receive the good news that, after comparing Cr12MoV, DC53, 8566 (four-pass), and 6mm 40Cr cold heading steel, Yuhui\u2019s 8566 still had the longest service life.<\/p>\n\n\n\n

 I believe there are many others facing similar cold heading conditions where their dies are prone to chipping, resulting in short service life. That\u2019s why I\u2019m documenting this case and sharing it with everyone\u2014so that when cold heading dies chip, people will think of 8566 anti-chipping steel and avoid the frustration of chipping.<\/p>\n\n\n\n

\u00a0Using 8566 die steel<\/a> <\/strong>for punch chipping makes all the difference\u2014it\u2019s like night and day.<\/p>\n\n\n\n

*************<\/p>\n\n\n\n

Wu Dejian’s\u00a0tool\u00a0steel<\/a><\/strong>, the chief of staff of the user, bought everything he had used.<\/p>\n","protected":false},"excerpt":{"rendered":"

Yesterday, Mr. Shi came to Yuhui again to purchase 8566 crack-resistant steel, and he told me: \u201cFor cold heading dies, 6.0 40Cr forming dies are prone to cracking. I\u2019ve tried Cr12MoV, DC53, 8566 from a fourth-hand supplier in Ningbo, and Yuhui\u2019s 8566. After comparing them, your Yuhui 8566 die steel still has the longest service life.\u201d […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1453","post","type-post","status-publish","format-standard","hentry","category-blog"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t