China fastener factory's hot-dip galvanized bolt protection performance, usually electro-galvanized bolt layer thickness is 5-15μm, while the hot-dip galvanized bolt layer is generally above 65μm, even as high as 100μm. Hot-dip galvanized bolts have good coverage, dense coating and no organic inclusions.

As we all know, the anti-atmospheric corrosion mechanism of zinc includes mechanical protection and electrochemical protection. Under atmospheric corrosion conditions, there are protective films of ZnO, Zn(OH)2 and basic zinc carbonate on the surface of the zinc layer, which can slow down the corrosion of zinc to a certain extent. When the layered protective film (also called white rust) is damaged, a new layer will be formed. When the zinc layer is seriously damaged and the iron substrate is endangered, zinc will produce electrochemical protection for the substrate. The standard potential of zinc is -0.76V, and the standard potential of iron is -0.44V. When zinc and iron form a micro battery, zinc is dissolved as an anode. It is protected as a cathode. Obviously, China industrial full threaded stud supplier's hot-dip galvanizing has better atmospheric corrosion resistance to base metal iron than electro-galvanizing.