400 Series Stainless

The 400 series includes both ferritic and martensitic steels.

Ferritic steels: non-hardening steels,  ideal for conditions in elevated temperatures. Typical applications for ferritic stainless steels include petrochemical, automotive exhaust systems, heat exchanges, furnaces, appliances and food equipment to name a few.

Martensitic steels: able to be hardened, ideal for a wide variety of common uses. Martensitic stainless steels are used extensively in cutlery, sport knives and multi-purpose tools.

The table below shows common types of 400 series steel:

400 Series Applications Type 405 a ferritic steel, used especially for welding applications Type 408 heat-resistant; poor corrosion resistance; 11% chromium, 8% nickel. Type 409 cheapest type; used for automobile exhausts; ferritic (iron/chromium only). Type 410 martensitic (high-strength iron/chromium). Wear-resistant, but less corrosion-resistant. Type 416 easy to machine due to additional sulfur Type 420 Cutlery Grade martensitic; Excellent polishability. Type 430 decorative steel, used for automotive trim; ferritic. Good formability, but with reduced temperature and corrosion resistance. Type 440 a higher grade of cutlery steel, with more carbon in it, which allows for much better edge retention when the steel is heat-treated properly. Type 446 For elevated temperature service