400 Series-Ferritic and Martensitic Stainless Steel

Type 408-Good heat resistance, weak corrosion resistance, 11% Cr, 8% Ni.

Type 409-the cheapest type (British-American), generally used as car exhaust pipe, is a ferritic stainless steel (chrome steel).

Type 410-Martensite (high-strength chromium steel), good wear resistance and poor corrosion resistance.

Type 416-Added sulfur improves data processing capabilities.

Type 420- “blade grade” martensitic steel, similar to the earliest stainless steel of Brinell high chromium steel. Also used in surgical knives, it can be very bright.

Type 430-ferritic stainless steel, for decoration, such as for car accessories. Outstanding moldability, but poor temperature resistance and corrosion resistance.

Type 440-high-strength cutting tool steel, which contains slightly higher carbon, can obtain higher yield strength after proper heat treatment, and the hardness can reach 58HRC, which is classified as the hardest stainless steel. The most common use is, for example, a “razor blade”. There are three common types: 440A, 440B, 440C, and 440F (easy to process).