Some narrow edge punches may crack, but you really use 8566 anti collapse steel.
I just received a consultation from a netizen. He punched a 1.25-thick 62 copper with a punch width of only 0.7mm. The punch wall thickness is smaller than the plate thickness, and the punching ratio is less than 1:1. Now, he uses SKH-9 to punch 1-2 thousand products and the punch will break. He has switched to ASP23 powder high-speed steel, which has a much better service life and can punch normally. However, he only punches 30000 to 50000 products, and the narrow edge of the punch will crack. He asked me what kind of mold steel should I use?
Although production is now possible, the price of ASP23 is too expensive. The cost of processing the punch may be even more expensive than the material cost, and if you use high-speed punching, you need to replace the punch after 30000 to 50000 strokes, which results in high time and cost delays.
Although the smelting quality of ASP23 is better than SKH-9, avoiding fine cracks and having stronger anti cracking performance of the punch, its price is more than twice that of SKH-9. Despite being several hundred and one kilogram larger, it can only be punched 30000 to 50000 times, and the frequency of punch replacement is too high, making production efficiency impossible.
For molds with a punch wall thickness smaller than the plate thickness, the priority should be given to anti cracking performance, rather than choosing ASP23 powder high-speed steel with higher hardness and higher price. Narrow edge punch cracking, I recommend using 8566 anti collapse steel.
The anti cracking performance of 8566 is four times that of high-speed steel SKH-9 and twice that of D2, with a hardness of 58-60HRC. It mainly solves the cracking problem that cannot be solved by high hardness mold steels such as D2, DC53, and SKH-9. Especially in stainless steel stamping, sharp corner stamping, narrow edge stamping, and even narrow edge working conditions where the width of the punch is less than the plate thickness and there are few overlapping edges, and even cruel working conditions where the stamping ratio is less than 1:1, the cracking that cannot be solved by conventional mold steel is solved by using 8566 anti collapse steel.
We have a customer who stamps copper material with a thickness of 0.7mm, and the narrow edge of the punch is only 1mm. When using SKD11, the punch life never exceeded 100000 times, and every time it was punched 30000 to 50000 times, the narrow edge position would crack, and we couldn’t find a solution. He later solved the problem with 8566 anti collapse steel, with a punch life of over 700000, finally breaking the curse of a punch life of only 100000.
For narrow edge working conditions where the material being punched is not too hard, the punch wall is very thin, or even the stamping ratio is less than 1:1, and there are few overlapping edges, using SKH-9 is prone to cracking. Therefore, you should think of 8566 anti collapse steel instead of using ASP23, which is more expensive and has better smelting quality. Using SKH-9 for narrow edge working conditions is a material error, and using ASP23 is a waste of money due to improper material selection.
But if you use 8566 anti collapse steel, it won’t crack and save costs, which means you can achieve punch cracking. With 8566 die steel, the old and new societies are on a dual footing.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.