Galvanization adds a layer of zinc to the exterior of steel to enhance its corrosion resistance. Although several methods of galvanization exist, hot-dipping creates a metallurgical bond between the zinc and the steel substrate and so offers the best protection against corrosion. Fasteners are lowered into a vat of molten zinc at a temperature of about 850°F. The American Galvanizers Association claims that a damaged area of the coating up to ¼ in. will continue to receive protection from the surrounding zinc. Because the zinc coating is sacrificial, however, it eventually will corrode. Still, the cost of HDG fasteners (and any connectors used with them) is so much lower than that of stainless-steel fasteners that they are the common choice for noncoastal areas. Be sure that the HDG nails and connectors you use meet the ASTM A153 standard, which ensures that the zinc coating is of a sufficient quality and thickness.
The distinctive rough appearance of HDG nails is not found on HDG bolts and screws, which are spun in a centrifuge to clear the threads of excess zinc. Still, there’s enough coating remaining on the threads that nuts have to be tapped oversize to fit the bolts. Nongalvanized nuts won’t fit, but they shouldn’t be used anyway. HDG bolts and screws are subject to an additional ASTM standard, F2329, which regulates HDG threaded fasteners.Cost
: $15 for 5 lb. of 3-in. 10d nails