ISO 12944-4:2017 covers the following types of surfaces of steel structures consisting of carbon or low-alloy steel, and their preparation:

- uncoated surfaces;

- surfaces thermally sprayed with zinc, aluminium or their alloys;

- hot-dip-galvanized surfaces;

- zinc-electroplated surfaces;

- sherardized surfaces;

- surfaces painted with prefabrication primer;

- other painted surfaces.

ISO 12944-4:2017 defines a number of surface preparation grades but does not specify any requirements for the condition of the substrate prior to surface preparation.

Highly polished surfaces and work-hardened surfaces are not covered by ISO 12944-4:2017.