HDG C, also known as hot-dip galvanized steel C-shaped steel, is immersed in about 470 degrees C steel melted zinc solution, one method of alloying metal covering. In recent years, with the rapid development of modern industry, galvanized C-shaped steel has been applied to many areas, HDG has the advantage of anti-corrosion life long, broad environmental adaptation has been very popular with people welcome, so hot dip galvanized C-shaped steel protection requirements have become more sophisticated, the demand for hot-dip galvanized steel C is also increasing, and gradually replace the traditional galvanized C-shaped steel technology. I-beam method is now used mainly galvanized surface is galvanized. Cold-formed steel (coldrolledsectionsteel) refers to the use of steel or steel bent in the cold state into a variety of cross-sectional shape of finished steel. Cold-formed steel is lightweight thin-walled steel cross section an economical, also known as cold-formed steel cold-formed profiles or profiles. Cold-formed steel is the main material for the production of light steel structure. It can not be produced with a variety of hot-rolled special thin, reasonable and complex cross-sectional shape.