What is "sherardizing"

Vapor galvanizing \Va"por gal"va*niz`ing\ (Metal.) A process for coating metal (usually iron or steel) surfaces with zinc by exposing them to the vapor of zinc instead of, as in ordinary galvanizing, to molten zinc; -- called also Sherardizing. Vapor galvanizing is accomplished by heating the articles to be galvanized together with zinc dust in an air tight receptacle to a temperature of about 600[deg] F., which is 188[deg] below the melting point of zinc, or by exposing the articles to vapor from molten zinc in a separate receptacle, using hydrogen or other reducing gas to prevent oxidation.