This part of ISO 12944 deals with 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. This part of ISO 12944 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 this part of ISO 12944.