A. Shalea Hardison responds: There are several methods for coating steel with zinc. The most commonly used for nails, bolts, and screws are hot-dip galvanizing, mechanical galvanizing, and electroplating. The coatings resulting from the different methods have different characteristics and provide varying levels of corrosion protection (see chart below).
Hot-dip galvanizing is the process of dipping steel into a bath of molten zinc, creating a series of metallurgically bonded zinc-iron alloy layers. The fasteners are typically dipped in baskets, then placed in a spinner, or centrifuge, to remove the excess zinc from the threads. The minimum coating thickness for hot-dip galvanized fasteners...
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