Stainless Steel Grade 309 and 309S are austenitic chromium-nickel stainless steels that are frequently utilized for higher temperature applications. Because of their high chromium and nickel content, Alloys 309 and 309S are highly corrosion resistant, have greater resistance to oxidation, and magnificent heat resistance while giving good qualities at room and high temperatures. The difference between Stainless Steel 309 and 309S is the carbon content. Alloy 309S has a substantially less carbon composition which reduces carbide precipitation and improves weldability. Characteristics