Selection of specific stainless steel grades is based on experience and knowledge about the performance of specific grades with regard to the environment.

Atmospheric environments are most commonly divided into four categories: rural, urban, industrial and marine. The environments vary depending on the severity from a corrosive point of view.

Atmospheric corrosion occurs on a steel surface in a thin wet film created by the humidity in the air in combination with impurities. Corrosive conditions for stainless steel can be the chloride depositions from a marine atmosphere on the steel surface in a humid atmosphere these, conditions may alter the choice of steel grade to a more corrosion resistant alloy.

The type of corrosion is most commonly local in the presence of chlorides, i.e. pitting or crevice corrosion. Molybdenum-alloyed grades of type 316 or comparable grades are normally specified for a marine atmosphere, regardless of whether the application is a prestigious building in a coastal city or an offshore platform. However, this material has inadequate resistance if used close to the sea in tropical countries with high levels of humidity and high daytime temperatures.

The importance of keeping the surface clean by regular washing to avoid staining and dust cannot be stressed enough.