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.