431 grade is a Martensitic stainless steel grade. It contains both chromium and nickel. With heat treatment its tensile strength can be significantly increased. The 431 grade materials transit the heat well and they are very suitable for polishing. One of the significant properties of the 431 grade is its good surface structure even under high temperatures.

​

Due to its lower carbon level, its hardness values are below other Martensitic grades, but thanks to its nickel content, its corrosion resistance is much higher. The 431 grade is also known as 4057 and 1.4057.