Galvanized vs. Zinc-Coated Fence Posts: What's the Difference?

A homeowner installing wrought iron fence asks about the difference between galvanized and zinc-coated posts.

Both use zinc, but thickness differs: zinc plating is ~3 microns; hot-dip galvanizing is ~50 microns, providing 10x the protection. Hot-dip galvanizing immerses steel in molten zinc (~860°F), forming a zinc carbonate patina that resists corrosion. The crystallization pattern (spangle) identifies galvanized steel. All true galvanizing is hot-dip; some paints misleadingly use the term.