21Cr-6Ni-9Mn is a high maganese nitrogen strengthened, austenitic stainless steel that combines high strength in the annealed condition, excellent resistance to oxidation at high temperatures, good resistance to lead oxide and a high level of corrosion resistance at ambient temperatures. The alloy can be fabricated and formed much the same as Type 304 and 316, and is readily weldable. It remains nonmagnetic after severe cold work.

21Cr-6Ni-9Mn has been used for chemical process and pollution-control equipment, steam and autoclave applications, and various aircraft engine components, as well as numerous other applications.