409 stainless steel is a ferritic stainless steel commonly used in machinery, construction and other engineering. Because of the existence of austenite grains, the mechanical properties have been greatly improved. And because of the addition of many alloying elements, the strength and hardness are also greatly improved.

Chemical Composition of 409 Stainless Steel
chemical composition	content
C	≤0.08
Si	≤1.0
Mn	≤1.0
Cr	10.50～11.75
Ni	≤0.50
S	≤0.03
P	≤0.045
Ti	6C～0.75