The extent to which galvanized steel should be alloyed with Fe was studied in view of press formability. The buildup of delaminated coating on a die shoulder cannot be reduced by decreasing the coating thickness. Buildup can, however, be reduced by thinning the η phase. In half-alloyed coating where η and ZnFe-alloy phases exist together delamination does not occur due to biaxial stretching deformation as it does in conventional galvanized coating. It occurs from the Γ phase due to drawing deformation as it does in galvannealed coating. Half-alloyed galvanized steel can, therefore, be applied for a thicker-coated corrosion-resistant material with excellent press formability.