Name	HDG	Pre Galvanised	Galvalume	electro-galvanized
Description	hot-dip galvanization process involves immersing the entire finished steel product, or “steelwork”, in a bath of pure liquid zinc. This ensures complete coverage of the product, including the inside surfaces of any hollow areas (such as the inside of a tube)	When steel componants are galvanized before the final product is assembled, it is known as pre-galvanization, or “pre-gal”.	Invented by Bethlehem Steel in 1972, the patented Galvalume manufacturing process is similar to galvanization but with aluminum and silicon added to zinc. As the coating dries, patches of aluminum and zinc molecules coalesce into a pattern across the surface of the sheet. The aluminum areas provide corrosion resistance, while the zinc provides galvanization protection. The small amount of silicon helps the coating adhere to the underlying metal, even when cut or rolled into the corrugated shape.	cold galvanizing, is to use electrolysis devices work piece through the degreasing, pickling ingredients post into the zinc salt solution, and connect the anode electrolysis equipment;
Coating thickness	Thick	Thin	The thicknesses of the Galvalume are approx 1 mil thick. Its manufacturing includes the hot-dip process, and basically, thickness difference depends on the coating.
Notes			Extra corrosion resistance
Service Life			at least TWICE the service life of traditional zinc-coatings
Finishing	Average			Best