I have some good news to share with everyone. Mr. Lan came back today and told me: “The service life of your 8566 cold heading bolt dies can range from 6,000 to 17,000 cycles. The service life is comparable to that of the previous tungsten steel dies, but 8566 costs only one-fifth the price of tungsten steel. This material is truly excellent.” I’ve already recommended you to three of my colleagues so they can start using 8566 chipping-resistant steel as well—good things are meant to be shared with friends.
I’m very pleased to hear this. Cold heading dies are subjected to external impact forces, and some die failures result from cracking or chipping. What you need to improve is the toughness of the die steel, not its wear resistance. In terms of wear resistance, 8566 anti-chipping steel certainly can’t match tungsten carbide, but 8566 offers better toughness than tungsten carbide at a lower price.
Mr. Lan is cold heading 20-diameter hex bolts with 70 teeth on the back of the bolt. He is currently using tungsten carbide as the die insert material. The die is secured with a clamping sleeve, but the teeth are prone to chipping. Sometimes the die lasts for over 20,000 cycles, and other times only 10,000—either the R-corner of the teeth flips up, or a large chunk breaks off; A tungsten carbide die costs 6,000 yuan, so the loss from die chipping is significant. He has also tried using DC53, but the dies were prone to cracking.
Since his die has teeth—similar to the structure of a lock washer with many serrations—and features sharp corners and fine teeth, he needs to prioritize chip resistance over wear resistance. I recommended that he use 8566 chip-resistant steel.
8566 offers four times the crack resistance of SKH-9 high-speed steel and twice that of D2, with a hardness of 58–60 HRC. It is specifically designed to address the cracking issues that high-hardness die steels such as D2, DC53, SKH-9—particularly in applications such as stainless steel stamping, sharp-corner stamping, narrow-flange stamping, thick-plate stamping, and cold heading dies. Cracking issues that standard die steels cannot resolve are all addressed by 8566.
When Mr. Lan first tried 8566, he remarked that its service life was 20 times that of DC53. Today, he returned to tell me that 8566’s service life ranges from 6,000+ to 17,000 cycles—comparable to that of tungsten carbide dies—but at only one-fifth the cost. In comparison, 8566’s cost-effectiveness is clearly superior.
So-called value for money isn’t just about being cheap; you must first have quality and performance. Only on this foundation can we truly talk about value for money. The fact that 8566 molds have a service life comparable to tungsten carbide while reducing costs by 80%—that’s what we call value for money.
Mr. Lan is very pleased; he has shared this information with his friends, hoping they’ll also start using 8566 anti-chipping steel, which offers excellent resistance to chipping.
To be honest, I’m also very pleased that 8566 performs so well in toothed molds. It has the same service life as tungsten steel, costs only one-fifth as much, and doesn’t chip—the value-for-money advantage is clear.
If you also manufacture stop bolts and have previously struggled with tungsten steel molds that crack easily—if you haven’t been able to solve the problem and aren’t sure which material to use—then you should give 8566 crack-resistant steel a try.
Using 8566 die steel for punch cracking makes all the difference—it’s like night and day compared to the old methods, and everyone who’s tried it is convinced.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.