Hot-dip galvanizing, like other coatings, isolates the steel from the environment providing basic, barrier protection. The intermetallic layers of the zinc coating are tightly bonded (~3600 psi) to the base steel making damage difficult. Galvanizing also provides cathodic protection, meaning the zinc will sacrifices itself to protect the underlying steel. Even if the coating is scratched, the surrounding zinc will continue to resist corrosion of the steel.