The 409 Stainless Steel Plate is made up of general purpose martensitic stainless steel, which has 12% chromium in its chemical composition. The material can be heat treated to get a wide range of enhanced mechanical properties. The ASTM A240 SS 409 plate is known for possessing high strength and hardness. They can also resist corrosion effectively. The AISI 409 Plate is quite ductile in the annealed condition and comes with a high formability. It stays magnetic in both heat treated and annealed conditions.