While all common steels can be galvanized, the chemical composition of a particular steel can affect the formation, thickness and appearance of its galvanized coating, as well as the ability of that coating to withstand mechanical damage. Additionally, the prior history of  the steel (e.g. whether it is hot rolled, cold rolled, blasted, welded or thermally cut) can also effect the galvanized coating. This is important, as the corrosion resistance of galvanized steel is directly related to the thickness of its coating. 

The elements silicon (Si) and phosphorus (P) have a critical impact on galvanizing. These elements can prolong the reaction between iron and zinc, which consumes the pure outer zinc layer of a coating, and results in the zinc-iron alloy layer being exposed. Pure zinc coating provides steel with a shiny metallic finish, whilst zinc-iron alloys result in duller grey colours. This phenomenon is described by the curve on the right.