Tool steels are a family carbon and alloy steels having distinct characteristics such as hardness, wear resistance, toughness, and resistance to softening at elevated temperatures. Tool steels comprise carbide-forming elements such as chromium, vanadium, molybdenum and tungsten in different combinations. Tool steels are frequently used for the shaping of other materials. Types of tool steel include hot work, cold work, plastic mould and high speed steel. The choice of steel for a particular application depends on which tool steel properties suit best, such as the required hardness, shock resistance, strength and toughness. Other considerations include the working temperature, abrasion resistance and working environment. Tool steels are used for shaping metals, plastics, glass forming in glass-works, woodworking, paper production, guillotines, blades, drill bits and cutting tools. These are just examples of applications, and the term "tool steel" is permanently granted by the tools made of it during the initial development of the whole subgroup. Today the scope of application is so wide that it is hard to unambiguously catalog all grades to one department.