Material has to possess good flatness, uniform hardness and high elasticity.
The term has no reference to the acidity of the steel. These changes, which bring about a condition of increased hardness, elastic limit, and tensile strength with a consequent loss in ductility, occur during the period in which the steel is at normal temperatures. Such steels attain their martensitic structure without going through the quenching process. Additions of chromium, nickel, molybdenum and manganese are effective toward this end. The common name for a type of clad wrought aluminum products, such as sheet and wire, with coatings of high-purity aluminum or an aluminum alloy different from the core alloy in composition.