Mirror plastic mould steel PMS
Mirror plastic mould steel PMS, or pre-hardened mould steel (pre-hardened steels, PM) is a versatile material that is suitable for the manufacture of tools and precision components used in the plastic injection mould industry.
The steel contains alloying elements including chromium, molybdenum and vanadium to give it the necessary hardness and strength to withstand the heat generated during the injection moulding process. The alloying elements also give the material good resistance to wear, abrasion and corrosion. The steel can be supplied in a range of hardness grades ranging from 35 to 50 HRC.
The material is produced in a range of sizes and the steel can be supplied in flat, round or square bars, rods and sheets. The steel can also be supplied in pre-hardened state or can be heat treated and tempered to meet the required hardness levels.
The material has excellent machinability and can be worked using traditional machining techniques such as drilling, turning, reaming and milling. For increased machinability the material can be supplied in an annealed condition, however this should only be done for components that require little or no heat treatment. The steel can also be supplied in a pre-hardenedstate and achieving the required surface finish is usually fairly straightforward.
The steel has good weldability and can be welded using both oxy-acetylene and arc welding techniques. However, if welding is required the steel should be supplied in an annealed condition to minimise any welding distortion.
During the injection moulding process the steel is subjected to high temperatures and the resistance to heat related distortion is an important factor to consider when selecting the material for an injection moulding application. The steel has excellent thermal stability due to the addition of molybdenum, chromium and vanadium, thus providing good resistance to thermal other impurities.
The material is used extensively in the manufacture of high precision moulds such as caps, closures and containers. It is also used to produce large injection moulds for automotive components, home appliances, electrical and electronic components and other demanding plastic parts.
For optimum performance PGM recommends that mirror plastic mould steel PMS is washed and cleaned prior to use and its suitability should be determined before it is used in any critical applications. Additionally, the material should be kept dry and protected from high temperatures and corrosive environments to prevent any damage to the finished parts.
