Requirements for mold steel materials for mold making:

1. Easy to process. Injection mold parts are mostly made of metal materials, and the structural shapes of some mold parts are very complicated. In order to shorten the mold making cycle and improve efficiency, the mold materials are required to be that it is easily processed into the shape and precision required by the mold design drawings.

2. Good wear resistance. The gloss and precision of the plastic part surface are directly related to the wear resistance of the mold cavity surface. Especially when plastic is added with glass fiber, inorganic filler and some pigments, they and plastic flow together with high speed in the runner and the cavity, which have great friction affection on the mold cavity surface. If the mold material is not wear-resistant, it will be worn quickly and the quality of the injection molding plastic part will be lowered.

3. High Corrosion Resistance. Many resins and additives have corrosive effects on the mold cavity surface. This corrosion causes the metal of the mold cavity surface to corrode and peel off, the mold surface condition deteriorates, and the quality of the injection molded part deteriorates. Therefore, it is best to use corrosion-resistant mold steel or the mold cavity surface is performed chrome-plated and nickel-plated.

4. Good dimensional stability. During injection molding, the temperature of the injection mold cavity will reach above 300 °C. So, it is best to choose and use a suitably tempered mold tool steel (heat treated steel). Otherwise, it will cause a change in the microstructure of the material, resulting in a change in the mold dimension.

5. Small effect caused by heat treatment. In order to improve the hardness and wear resistance, the mold is generally subjected to heat treatment, but this treatment should be such that the dimensional change is small. Therefore, it is preferable to use pre-hardenable mold steel that can be machined.

6. Good polishing performance. Plastic parts usually require good gloss and surface condition. Therefore, the mold cavity surface roughness is required to be very small. Therefore, the cavity surface must be surface-processed, such as polishing and grinding. Therefore, the selected steel should not contain rough impurities and pores.

Plastic mold steel with good cutting and polishing properties. This mold steel has fewer impurities, fine and uniform microstructure, no fiber orientation, and high mold cavity surface quality after mold making.

Pre-hardened plastic mold steel. This mold steel has widely application, and it is supplied with the form of pre-hardened steel blocks. The hardness reaches 23~48HRC. It is no longer processed after processing the cavity, and there is no deformation, which can shorten the mold manufacturing cycle. The representative steel number is:

Age hardening plastic mold steel. The steel generally has low carbon content, and the steel is added with elements such as Ni, Al, Ti, Cu, Mo, etc.

Corrosion resistant plastic mold steel. Some plastic products contain polyvinyl chloride, fluoroplastics, flame retardant plastics, etc., which have corrosive effect on the mold during plastic molding. So, martensitic stainless steel and precipitation hardening stainless steel are generally used. When the order is low volume injection molding, and has no high requirements, chrome protection measures can be taken on the mold surface. But in most cases of plastic processing, injection molds made of corrosion-resistant steel are required.

Mold material selection is a very important part of the entire mold making process. When selecting mold steel, comprehensive consideration should be given to its working conditions, failure, performance, etc. Selecting plastic mold steel materials reasonably to improve the mold service life and reduced mold manufacturing costs.

Mold steel ACO Mold frequently used:
1.2344, 12343, S136, LKM2316, LKM738H, 1.2083, 1.2312, 1.1730, H13, P20, MOLDMAX-HH.