Hot-dip galvanizing is a process of applying a protective zinc coating by dipping product in bath of molten zinc. Galvanizing is a favored method of protective coating due to its low cost, ease of application, and long maintenance-free service life. Generally applied at 830 to 870 degrees, the zinc will bond with the steel. It is the most common outdoor protective coating in use. When used on bolts, due to the thickness of the zinc coating, all galvanized nuts must be tapped oversize.
Zinc plating or electroplating is a process where zinc is applied by using a current of electricity. It is a thinner coating than hot-dip galvanizing making it unsuitable for outdoor applications. Its advantages are its brightness and uniform color making it more aesthetically appealing.
The ASTM specification covering hot-dip galvanized fasteners is F2329, while the specification covering zinc plated fasteners is F1941.
How the threads of HDP A325 bolts and nuts are treated to accommodate the additional layer of zinc on the threads of both pieces?
@A Gardener- The internal threads of the nut are tapped oversize to accommodate the zinc thickness.
How to remove zinc after hot dipping if it is stuck in between ms pipe and sleeve
@Omkar- Without actually seeing the part, our guess is that you could strip the part using the same acid bath that is used in the cleaning and pickling process. If that is not an option, you may have to consult someone with a bit more knowledge of the specific application.