The product is manufactured 45# steel and scale of 300-ton forging press forging manufacturing while operating Crack-free-non crack technology in order that not easy to deformation after the heat treatment. Electroplating technology achieve the requirements of there nickel-plating-one chromium-plating, chromium layer thickness of 8??m, the surface is not easy peeling off; salt spray test is up to seven degree so as to be strong to anti-rust,anti-deformation.