The Chinese brand corresponding to 309S is 0Cr23Ni13, and the American standard S30908 (AISI, ASTM) has better corrosion resistance and heat resistance than 0Cr19Ni9.

309s is a variant of 309 stainless steel with a lower carbon content, used in situations where welding is required. The lower carbon content minimizes the precipitation of carbides in the heat affected zone near the weld, which may lead to intergranular corrosion (welding erosion) of stainless steel in certain environments.