Of plastics; They are tool steels used in shaping with injection, extrusion, blow molding and various pressing techniques. Plastic moulding is a part of our everyday lives. Car parts, mobile phones, spectacles and computer chassis are all manufactured in moulds. However, the materials needed to make these moulds often require unique and demanding characteristics. This is why it is crucial to select the correct steel grade for your specific mould. Harsh environments put steel under considerable stress. The problems are well-known, choosing the right tool steel is the solution. A moulder knows that the cost of excessive mould maintenance, e.g. major repolishing, clean- ing, replanting and replacing of worn or broken parts has to be taken into account. The costs of production and down time, overtime payment, late-delivery penalties and loss of customer good- will also need to be considered.