The chemical composition of standard types of wrought stainless steels are listed in ASTM Specification A240. The UNS 20000 series designates nickel-chromium manganese, corrosion resistant types that are nonhardenable by thermal treatment. The UNS 30000 series are nickel-chromium, corrosion resistant steels, nonhardenable by thermal treatment. The UNS 40000 however, includes both a hardenable, martensitic chromium steel and nonhardenable, ferritic, chromium steel. Reference to SAE J412 is suggested for general information and usage of these types of materials. See

Table 1 .