Hot dip galvanizing is an effective way of metal anticorrosion, which is mainly used in metal structure facilities of various industries. It is to immerse the derusted steel into the molten zinc solution at about 500 ℃, so that the surface of the steel members is attached with zinc layer, so as to achieve the purpose of anti-corrosion. The galvanized layer is relatively firm.
Hot dip zinc galvanizing is available for many fasteners. Threads in the nuts must be tapped oversized after galvanizing, or the parts will not assemble. This coating is very effective in salt atmosphere because it is applied approximately 2 mils thick. Because of the need to tap the nuts after galvanizing, the inside of the nut forms corrosion that will not allow disassembly after a period of time.
Stv Valve does not recommend Hot Dip Galvanizing for medium to high strength alloy parts used in the
production of oil and gas, because of the chance of hydrogen embrittlement, and the tendency for the
thickness to vary, causing uneven torque readings upon application.