420 stainless steel is a hardenable, martensitic stainless steel that is a modification of Alloy 410. Similar to 410, it contains a minimum of 12% chromium, just sufficient enough to give corrosion resistant properties. 420 stainless steel has higher carbon content than 410 stainless steel which is designed to optimize strength and hardness characteristics. It has good ductility in the annealed condition but is capable of being hardened to a minimum Rockwell hardness of 50 HRC, the highest hardness of the 12% chromium grades. Due to its hardening properties, 420 stainless steel is not often welded, although it is possible. Martensitic stainless steels are designed for high hardness and sometimes other properties are to some degree compromised. Corrosion resistance is lower than the common austenitic grades and their useful operating range is limited by their loss of ductility at sub-zero temperatures and loss of strength by over-tempering at elevated temperatures. Its best corrosion resistance is achieved when the metal is hardened and surface ground or polished.

Chemical Properties

C Mn Si P S Cr
420 0.15 1 1 0.04 0.03 min: 12.0
max max max max max max: 14.0

Physical Properties

Density Thermal Conductivity Electrical Modulus of Coefficient of Specific Heat
kg/m^3 W/mK Resistivity Elasticity Thermal Expansion (J/kg.K)
(Microhm/cm) µm/m/°C
7750 24.9 at 212°F 550 (nΩ.m) at 68°F 200 GPa 10.3 at 32 – 212°F 460 at 32°F to 212°F
– at 932 °F 10.8 at 32 – 599°F
17.7 at 32-1000°F

What Stainless Steel Grades We Have!

Qinghe Steel is a full line supplier and processer of stainless steel coil, sheet, plate, bar, and strip products. We stock many grades of stainless steel, including 300 and 400 series stainless, annealed and in various tempers and high temperature grades, for shipments worldwide. View our steel center here