Alloys made from copper, nickel, chromium, iron and aluminium constitute standard resistor materials with restricted tolerances concerning their electrical properties thus making them the preferred choice for certain applications. But also a number of other metals and metal alloys are suited as resistor materials provided that their properties conform with the specific requirements. The key dimensions for resistor materials are the specific resistivity and its dependency on temperature, the specific heat, density, corrosion behaviour and application temperature.