409 Stainless Steel is a stabilized ferritic stainless steel that provides improved oxidation and corrosion resistance compared to carbon steel. Ease of fabrication combined with its corrosion resistance and economy have significantly broadened its utilization in automotive exhaust and other non-automotive applications. ASTM A240 defines three (3) sub categories of Type 409 stainless steel; UNS S40910, UNS S40920 and UNS S40930. Each of these designations has a slightly different Ti or Nb stabilization requirement. Each of these compositions can be supplied as UNS S40900 unless the purchaser specifically identifies a specific composition. It is produced with enhanced formability characteristics known as “High Performance” or “Ultra Form” in the industry.
