321 stainless steel bar, also known as UNS S32100 and Grade 321, is primarily comprised of 17% to 19% chromium, 12% nickel, .25% to 1% silicon, 2% maximum manganese, traces of phosphorus and sulfur, 5 x (c + n) .70% titanium, with the balance being iron. With regards to corrosion resistance, 321 is equivalent to Grade 304 in the annealed condition and is superior if the application involves service in the 797° to 1652° F range. Grade 321 combines high strength, resistance to scaling and phase stability with resistance to subsequent aqueous corrosion.