Austenitic stainless steels are non-magnetic. When nickel is added to stainless steel in sufficient amounts the crystal structure changes to "austenite". The basic composition of austenitic stainless steels is 18% chromium and 8% nickel. This enhances their corrosion resistance and modifies the structure from ferritic to austenitic. Austenitic grades are the most commonly used stainless steels accounting for more than 70% of production (type 304 is the most commonly specified grade by far). They are not hardenable by heat treatment.

 Super austenitic grades have enhanced pitting and crevice corrosion resistance compared with the ordinary austenitic or duplex types. This is due the further additions of chromium, molybdenum and nitrogen to these grades.