Type 305 (UNS S30500)
Type 305 is a chromium nickel austenitic stainless steel with a low rate of work hardening due to the elevated nickel content. This low rate of work hardening makes this grade well suited for multi-stage deep drawing applications without process annealing where 304/304L may suffer from cracking issues. Type 305 is non-magnetic in the annealed and cold worked conditions and has corrosion resistance similar to 304/304L stainless steel.
Type 309 (UNS S30900)
Type 309 is a high temperature chromium nickel austenitic stainless steel that resists oxidation at temperatures up to 1900˚F in dry air at constant temperature. Under thermal cycling conditions this grade resists oxidation up to a temperature of approximately 1850˚F. Type 309 has good sulfidation resistance but low resistance to carburization and should not be used in highly carburizing atmospheres. Type 309 is non-magnetic in the annealed and cold worked conditions and is as resistant to corrosion as Type 304/304L.