AM Coatings

Adding magnesium to an aluminium dominant zinc-aluminium alloy coating improves the cut edge corrosion resistance to a similar level as zinc coating, but still confers the improved surface protection and slower erosion rate of AZ coatings.

Steel with a continuously hot-dipped coating of 47 - 57% aluminium and zinc, with the addition of 1 - 3% magnesium by mass is designated in AS 1397:2011 as AM.