As we all know, The key to producing a robust tool is to make the right choice in mold material. It can make quality parts over the life of the product.
In the international market, the price of mold steel is so transparent now, there is no secret that how much of the steel, copper, aluminum, and various alloys which used by the mold manufacturers. Over the past few months, the price had gone through the roof, almost impossible for us try to pin down the target price, So choosing the right mould materials is significant to a successful mold build.
Most of the tools companies builds use hardened tool steels. The type of material being run has a large impact on the steel selection due to the abrasion resistance or the corrosive properties of the steel. If a customer is running PVC materials, for instance, we will always recommend 420 SS [stainless steel]. If it is running glass-filled materials, we would recommend H-13 or S-7. In cases where the molds are for medical parts, most of the time we will use 420 or 440 SS so there isn’t the concern of rust and corrosion. Another area in which steel selection can be critical to building a robust mold is in areas where mold components are moving or rubbing against each other. We never have the same materials in areas where the components are moving against one another. In these cases, we like to use unlike materials with a hardness difference of no less than 2 points, or even more if possible.
According the number of the cycles + parts + volume required, the type of plastic material which will be used, the price the customer will pay for the mold. All of them are considerations for us to choose the right mold materials.
Another consideration is the type of water being run through the moulds. Some of our customers have problems with their cooling water being corrosive. If this is the case, we suggest 420 or 440 SS so that the waterlines do not corrode. Most customers don’t understand how much heat transfer is lost because of rusted waterlines. This results in a loss of production that could be avoided if the toolmaker or the customer had paid attention to their steel selections.