At noon today, an “uninvited guest” showed up. Luckily, I was at the factory; otherwise, he would have come by for nothing again.
Just before 12:00 p.m., I received a call from Mr. Su. He said the die for cold extrusion of 6-series aluminum had cracked, bringing production to a halt. A friend had told him that your company specializes in die steel for cold extrusion. Since I’m also in Liaobu, I drove straight over, but your factory wasn’t open.
I replied in surprise, “You’re already here at Yuhui Die Steel? It’s the weekend, so the workshop isn’t open, but I’m at the factory.”
After hanging up, I immediately went to pick him up. I was a bit puzzled—he hadn’t contacted me beforehand, so how did he find the factory so precisely?
After picking him up and seeing the product, I learned that he runs a hardware factory in Liaobu. He used to do stamping, but now he’s received an order for a cold-extruded product in a fairly large quantity. Although he’s never made cold-extruded products before, he wanted to give it a try. The cold extrusion involves small 12-diameter 6-series aluminum rods. The product doesn’t look complicated, but after making two sets of dies using SKD11 with a hardness of HRC 50, they could only produce a few pieces. When they increased the hardness, the dies cracked immediately, and production stalled. He reached out to many people, but no one could solve the problem. He visited friends in Chang’an and Dongkeng and consulted numerous others, but none seemed reliable. After countless revisions to the dies, he was at a loss as to what to do. He was even willing to hand the dies over to someone else if anyone would take them on. Finally, someone told him, “There’s a supplier in Liaobu who specializes in materials for cold extrusion dies—go straight to him; he should have a solution.” So he went straight to their shop.
SKD11 die steel used for cold-extruded aluminum profiles—even if the die doesn’t crack—is prone to aluminum shavings sticking to it and causing stringing, which makes production difficult. If you use the wrong material, it becomes very hard to fix later on; by the end, you’ll even feel like giving up.
I showed the two of them many samples, explained numerous case studies and phenomena related to cold extrusion of aluminum, and introduced the high-toughness LG die steel they were interested in.
They were particularly amazed and convinced after watching a video showing LG bending without breaking, and ultimately purchased the high-toughness LG die steel.
LG is a proprietary high-toughness die steel developed by Yuhui Company. Its toughness is 8 to 9 times that of DC53, with a hardness of HRC 54–58. It’s so tough that it won’t break even when bent by hand. For cold extrusion dies for aluminum, this die steel is the ultimate choice.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.