I. 4 types of stainless steel Currently, there are four types of stainless steel, also known as inox : Austenitic, Ferritic, Austenitic + Ferritic (Duplex), and Martensitic. 1 Austenitic: This is the most common type of stainless steel. There are many different grades in this group, such as SUS 301, 304, 304L, 316, 316, 321, […]