This specification covers two classes of oil-tempered steel spring wire intended especially for the manufacture of mechanical springs and wire forms. The steel may be made by any commercially accepted steel-making process and shall either be ingot cast or strand cast. The finished wire shall be free of detrimental pipe and undue segregation. The wire shall be oil quenched and tempered to produce the desired mechanical properties such as tensile strength. Cast, heat, and product analysis shall conform to the chemical composition requirements prescribed for carbon, manganese, phosphorus, sulfur, and silicon. Tension, wrap, and surface tests shall be performed. The surface of the wire as-received shall be free of rust, excessive scale die marks, pits, and scratches detrimental to the end application. Other metallurgical requirements such as microstructure and decarburization are detailed.