ron phosphating is applied when strong adhesion of a subsequent painting is required. In contrast to the solutions for Zinc phosphate and Manganese phosphate coatings, in which the metal ions are a constituent of the composition, to the iron phosphate solution iron ions are provided by the dissolving substrate. Iron phosphate coatings have very fine Grain structure. Iron phosphate is translucent therefore its color depends on the steel surface quality. The common color is blue or bluish-brown.Iron phosphate is applied mostly by spray (threestage or five-stage) method but immersion technique is also used. The coating weight is typically in the range 20-100 mg/ft2 (0.2-1.0 g/m2).