Water heater plays a role in the fastening screw in the water heater, it is not out of life, then you know the surface treatment type water heater screw? 1. The plating: plating parts immersed in containing by deposition of metal compounds in aqueous solution, the current through the plating solution and electroplating metal precipitation and deposition on the components and electroplating with zinc, copper, nickel, chromium, copper nickel alloy. 2. Hot dip galvanized by the carbon steel parts immersion temperature about 510 DEG C melting zinc plating bath finish. The result is steel parts on the surface of iron and zinc alloy gradually become products on the surface passivation of zinc, hot dip aluminizing is a similar process. 3. Mechanical plating: coating metal particles by the impact of the product surface, and the surface coating to the cold welding products.