Mr. Yan asked, “What type of die steel should be used for punches in aluminum stamping to prevent aluminum chips from sticking?”
He is stamping aluminum sheets that are 0.8 to 1.2 thick. Currently, the punches tend to accumulate aluminum chips. He is currently using Cr12MoV and DC53 punches, and even at relatively slow speeds, a standard punch accumulates a lot of aluminum chips. Once the chips stick to the punch, it causes scoring, and continued stamping becomes impossible.
Stamping aluminum tends to cause aluminum chips to stick to the die, which is the ultimate test of the quality of the die steel’s smelting process. If the die steel you use has segregation defects or microscopic cracks in its microstructure, the aluminum chips will penetrate into the die along these cracks during stamping, leading to the problem of aluminum chips sticking. As more and more aluminum chips accumulate, the product will develop scratches, and material jams may even occur.
Both DC53 and Cr12MoV are high-carbon cold-work die steels that contain microcracks in their microstructure. Coupled with the current fierce price competition in the die steel market and poor smelting quality, this has led to an increase in microcracks in die steel, making aluminum debris adhesion a very common issue.
To address aluminum debris adhesion during aluminum stamping, I recommend using 8566 anti-chipping steel.
8566 is a proprietary anti-spalling steel from Yuhui Mold Steel, designed primarily to address mold spalling issues; it has accumulated over a thousand successful case studies across five stamping operating conditions, six major material types, and seven major application areas.
8566 offers four times the chipping resistance of high-speed steel SKH-9 and twice that of D2, with a hardness of 58–60HRC. It can resolve chipping issues that high-hardness mold steels such as D2, DC53, and SKH-9 are unable to address.
The reason 8566 possesses such high chipping resistance lies not only in its optimal alloy composition but also—and crucially—in the quality of its smelting process. 8566 is produced using a critical gas electroslag furnace, resulting in mold steel with high purity and low levels of five major harmful impurities. It is further processed using a 4,500-metric-ton facility for six-sided forging—involving three forging passes and three drawing passes—which significantly improves microstructural segregation. This ensures excellent microstructural uniformity and eliminates microcracks caused by segregation, naturally preventing adhesion to aluminum chips.
Mr. Bao said excitedly: “When punching 4mm aluminum sheet with 8566, it doesn’t stick to the aluminum even after more than 10 days of operation. The punching speed has now been increased to 200 strokes per minute. No other die steel can achieve this—it’s amazed even the industry leaders.”
Mr. Bao was punching 4mm-thick aluminum sheets. When punching 45° sharp corners with DC53 or SKH-9, the corners would easily chip, and the punch would get clogged with aluminum powder. With a progressive die running at 100 strokes per minute for 10 hours a day, the punches would last about one day—sometimes requiring two punch changes a day, which was incredibly frustrating.
But now, using 8566 chipping-resistant steel, the punching speed has doubled from 100 to 200 strokes per minute, effectively doubling productivity—it’s like getting two days’ work done in one. The punch remains intact even after more than 10 days of continuous operation, representing a more than tenfold increase in service life compared to the previous daily punch replacements.
Doubled efficiency and a service life over 10 times longer—anyone would be thrilled. It’s no surprise that it stunned the industry leader; I’m sure even he has never seen such an amazing material.
Using 8566 die steel for punch chipping—it’s like night and day compared to the old days.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.