309 stainless in an austenitic chromium-nickel modification of 304 stainless with superior heat-resisting characteristics. It offers slightly better corrosion resistance than 304 because of the higher percentages of both chromium and nickel and possesses better creep strength than the straight chrome grades. 309 stainless possesses resistance to oxidation up to 2000ºF (1093ºC) in continuous services
