In addition to chromium, nickel, molybdenum, titanium and niobium, other elements may also be added to stainless steels in varying quantities to produce a range of stainless steel grades, each with different properties.

There are a number of grades to choose from, but all stainless steels can be divided into five basic categories:

 

These are named according to the microstructure inherent in each steel group (a function of the primary alloying elements). Austenitic and ferritic grades account for approximately 95% of stainless steel applications.