This specification covers two classes of uncoated, high-strength, hard-drawn steel wires for use in the manufacture of prestressed concrete pipe. The steel shall be made by the open-hearth, basic-oxygen, or electric-furnace process, and shall be free of injurious piping and undue segregation. The wire shall be cold drawn to produce the desired mechanical properties and there shall be no welds or joints in the finished wire. Cast or heat analysis of the steel shall conform to the chemical requirements specified for carbon, manganese, phosphorus, sulfur, silicon, and nitrogen. The tension and relaxation tests shall conform to the specified tensile requirements including tensile strength and breaking strength. Torsion test shall also be performed where test specimens shall be inspected for primary break shear area and longitudinal (spiral) splitting following completion of the test.