Between yesterday and today, I’ve received inquiries from two customers regarding the rapid wear of cold forging dies for optical modules.
Cold forging dies for optical modules experience rapid dimensional wear and require high precision. Currently, we’re using 8407 die steel, but the dimensions wear out and exceed tolerances within two days at most, and the die must be scrapped and re-machined. The re-machining surfaces are all made of hard copper material and processed via EDM, making the die manufacturing process very complex. The cavities require mirror-finish polishing, and the internal cavities of the parts produced are not subject to secondary processing. Currently, it takes a full week to make a die, but it can only be used for two days; after producing about 10,000 parts, it becomes scrap. Die production is too exhausting, Molds are scrapped too quickly, and we don’t have enough equipment to keep up. We urgently need to find a mold steel with excellent wear resistance to extend mold life and reduce the frequency of mold repairs.
These optical module parts are used for high-speed data transmission in current AI and big data applications. They require extremely high material density. Die-cast parts exhibit porosity and fail to meet the performance requirements for high-speed data transmission, so we must produce them using a cold extrusion strengthening process.
Furthermore, the internal cavities of the extruded products are not subject to secondary machining, so the requirements for geometric and dimensional tolerances are extremely strict. Since these parts undergo electroplating later, if the geometric tolerances are not guaranteed upfront, the parts produced after electroplating will be scrap.
After cold extrusion, the external surfaces of these parts require five-axis CNC machining, with machining costs exceeding 30 yuan per part. When factoring in the costs of electroplating and aluminum material, the resulting machining losses are prohibitively high. Consequently, the dimensional requirements for the internal cavities are extremely strict and must be verified using 3D coordinate measuring machines. If any dimensional deviations are detected, the mold is immediately scrapped. As a result, molds are being scrapped rapidly, and production cannot keep up with the demand for new molds.
That’s certainly true. It takes seven days to make the mold, but it can only be used for two days—it’s scrapped after producing about 10,000 parts. And since it’s made from hard copper using EDM, it’s a huge waste of time. The mold takes longer to make than it does to use; this kind of imbalance is very frustrating. It’s treating the mold as a consumable, trading the mold for parts, and the cost is simply too high.
For this type of mold, we need to enhance its strength to improve wear resistance and thereby extend its service life. You’ve already tried H13, which performed even worse, and you’ve also tested the harder DC53, which caused the mold to crack. This indicates that the mold requires a steel with better hardness than H13 and better toughness than DC53—a mold steel that is both hard and tough.
The 8407 die steel currently in use is a medium-carbon steel with a carbon content of 0.38% and a hardness of 50 HRC, but its strength is too poor. To improve strength, we must increase the total alloy content and raise the hardness. LG has a hardness of 54–58 HRC and toughness 8–9 times that of DC53. It is so tough that you can bend it with a hammer without breaking it. This ensures both strength and toughness, naturally improving wear resistance—this is the approach you should take when selecting materials.
Using LG die steel for aluminum cold heading dies will solve your cracking issues in a snap. You should definitely give this high-toughness LG diel steel a try.
In the past, when I heard the name NVIDIA or saw Jensen Huang, it didn’t seem to have anything to do with my mold steel business, so I didn’t pay it much attention. But recently, many of my customers in the optical module industry keep mentioning that our products are used by NVIDIA, and the order volume is huge. Ever since Jensen Huang launched a certain product, demand for these high-speed transmission products has really taken off.
It’s made me feel like my mold steel is now connected to AI and humanoid robots—it sounds pretty high-tech and sophisticated.
But you know what? Whenever something new like this comes along, machining, tooling, and mold steel experience a surge in demand. First it was smartphone casings, then electric vehicles, and now AI and humanoid robots—they all require product manufacturing and mold production, with increasingly sophisticated demands for precision, dimensions, and aesthetics.
As technology advances and standards rise, this is a major boon for our manufacturing sector. I also hope that our high-toughness LG mold steel can get a piece of the pie and grab a share of the action.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.