1. Boron (B) : Enhances screw the quenchability and helps to produce the desired reaction of low carbon steels to heat treatment.

2, manganese (Mn) : improve the strength of steel, and to a certain extent, improve the quenchability.Manganese can also improve surface quality by increasing the strength of hardened infiltration during quenching, but too much manganese is bad for ductility and weldability.And it will affect the control of electroplating coating.

3, nickel (Ni) : improve the strength of steel, improve the toughness at low temperature, improve the ability of atmospheric corrosion resistance, and can ensure the stable heat treatment effect, reduce the role of hydrogen embrittlement.

4, chromium (Cr) : can improve the quenchability, improve wear resistance, improve corrosion resistance, and is conducive to maintaining strength at high temperature.Drlling screw

5, Mo (Mo) : can help control the quenchability, reduce the sensitivity of steel to temper brittleness, has a great impact on improving the tensile strength at high temperature.

6, alum (V) : refine austenite grain, improve toughness.

7, carbon (C) : improve the strength of steel, especially its heat treatment performance, but with the increase of carbon content, plasticity and toughness decline, and will affect the cold heading performance and welding performance of steel.

8, silicon (Si) : to ensure the strength of steel, the appropriate content can improve the plastic and toughness of steel.