Martensitic stainless steels are magnetic and suitable for many applications Martensitic stainless steels are one of the four main types of stainless steels (Austenitic, Ferritic, Duplex, Martensitic). They were developed mainly to satisfy the property requirements for hardness, high strength, wear resistance, and corrosion resistance. They are also ferromagnetic, meaning that they can retain their magnetic properties after the magnetic field is withdrawn. Unlike ferritic and austenitic stainless steels, they can be hardened by heat treatment. However, due to their relatively lower chromium content, martensitic stainless steels are not as corrosion resistant as ferritic or austenitic stainless steels Martensitic stainless steels make up the 400 series of stainless steels. The 410 grade is the base grade and also the most commonly used one. It typically contains 11.5 – 13% chromium, 0.15% carbon, 0.1% manganese and is used in applications such as gas turbines blades and cutlery. 416 is another popular grade. It contains more chromium and manganese with an addition of molybdenum and sulphur/selenium, and it is used to make screws and gears.