This is a general purpose, commercial quality, Class I tensile, spring steel wire to ASTM A 229. With a quality between hard drawn spring wire and music wire, moderately priced OTMB is excellent for springs without servere bends. The material is cold drawn to the desired size and heat treated by a continuous tempering method. A low temperature stress relief is required after processing. Wire is available is size ranges from 0.023" - 0.625".