Custom 631 (17Cr-7Ni) is a semi-austenitic, precipitation-hardening stainless steel that provides high strength when sufficiently cold drawn and then aged. With corrosion resistance similar to 304 it is designed to provide an austenitic structure in the annealed condition with excellent cold drawability for high-strength wire applications. To achieve age-hardening properties, Custom 631 (17Cr-7Ni) must be cold drawn.