Galvanized fasteners are specially designed for outdoor use. They are also resistant against tannic acid present in wood and can be used in wooden furniture and other wooden products without the need for replacement frequently. Galvanized fasteners can last for a very long time if installed properly and without any damage.
The galvanized fasteners are durable like any stainless steel fastener but are much cheaper. The iron fastener cannot be used everywhere as they can get corroded and damaged very easily. The stainless steel fasteners, on the other hand, are not very strong and thus cannot be used for everything. The galvanized fasteners are ahead of both as they are not only durable but strong also.
There are two main types of galvanized fasteners available. The type is determined by the process of galvanizing. The galvanized fasteners are nothing but iron or some other metal fastener coated with zinc. It is either electroplated or hot-dipped in zinc for galvanizing. In the case of the hot-dipped galvanized fasteners, the zinc coating stays for a longer period of time but the threads of the fastener cannot be very fine and here the electroplated fasteners have the upper hand.
The galvanized fasteners are very strong and they are corrosion resistant. If the fasteners are dipped in the iron-zinc alloy the fasteners become even stronger than steel or iron fasteners. The galvanized coating can get damaged while you are tightening it but when the coating is hard, this possibility is nullified. When pure zinc is used for galvanizing, the coating is not so hard and it can be damaged.
The bonding between the zinc-iron alloy and the metal fastener is about 3600 psi. This bonding strength is high enough for the galvanized fastener to get damaged easily. Thus the protective coating remains for a long time and are not scratched easily. If the fasteners are galvanized using pure zinc the bond strength is a few hundred psi. This is also strong enough to sustain minor strains.
The galvanized fasteners are not damaged due to extreme temperatures. They remain intact and damage free in extreme climates. For this, the galvanized fasteners are used in many processing plants where the temperature can reach up to 200 degrees centigrade. Galvanized fasteners are also used by many plants and research labs in the arctic region. They are resistant to damage from extremely low temperatures and can last for years in such conditions.
When the fasteners are galvanized by the hot-dip method, the entire fastener is covered with the zinc-iron alloy uniformly. This ensures that there is no weak spot in the fastener which will get removed or corroded first. The edges and the corners of the fastener are completely covered with the corrosion-resistant material and the material of the fastener remains in its original state and is completely protected from the elements. While tightening the fastener, any sudden pressure does not remove the coating and the contact between the fastener and any other corrosive material cannot damage it.