The most significant order this morning came from Mr. Zhang, who works with PA66+GF30 injection molding. He has started purchasing 8503 mold steel—which resists sticking—in bulk, placing an order for 23 pieces today.
Mr. Zhang added me as a friend on September 9, 2020, and contacted me again on March 6 of this year: “Boss, the mold inserts corrode after a while. What mold steel do you recommend?”
After discussing the matter in detail, I learned that he was injection molding a generic brand of nylon reinforced with 30% glass fiber. Currently, his mold inserts are made from heat-treated S136 and DC53—not the most suitable materials. The molds can’t produce many parts before flash starts to appear on the product’s outer diameter. Upon inspecting the mold, I noticed signs of material erosion.
Injection molding of PA66 reinforced with 30% glass fiber—especially with such a high glass fiber content—causes severe erosion to the mold. The mold steel must possess both high wear resistance and non-stick properties; otherwise, the mold will be easily eroded, leading to flash on the product’s outer diameter. S136 and DC53—one has toughness but lacks wear resistance, while the other has wear resistance but suffers from severe segregation and numerous microcracks—are both unsuitable for this application. At the time, I recommended using 8503 mold steel, which resists material sticking.
8503 is a proprietary non-stick mold steel developed by Wu Dejian Mold Steel. It has twice the toughness of DC53 and a hardness of 55–61 HRC. Compared to DC53, its performance is doubled without a corresponding increase in price, and it offers the added benefit of being non-stick. In particular, this non-stick property, combined with its high hardness, is the fundamental and effective solution to the problem of molds used for materials with high glass fiber content—which are prone to being eroded, leading to flash on the product and surface roughness on the mold. Mr. Wan stated that for nylon with 30% glass fiber, the 8503 can withstand 1 million cycles without any issues.
After hearing the presentation, Mr. Zhang purchased a set of mold materials to test them out. Later, he ran out of 8503 steel on and off, but today—half a year later—he has begun purchasing 8503 mold steel in bulk. Today, he placed an order for 23 pieces across four specifications. The fact that the customer is willing to buy in bulk indicates that he recognizes the performance of 8503; it has already helped him resolve the issue of flash on his molds.
I am very pleased that our product can help customers solve problems and improve their efficiency. Every success story represents a milestone in our growth and is worth documenting.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.