Stainless steel round rod is a cylindrical stainless steel product widely used in auto parts, aviation, aerospace hardware tools, chemical industry and other industries. Stainless steel round bars can be divided into several categories according to their composition: Cr series (SUS400), Cr-Ni series (SUS300), Cr-Mn-Ni (SUS200) and precipitation hardening series (SUS600). Among them, Cr-Ni series stainless steel, especially 300 series stainless steel, has become the most widely used type of stainless steel due to its excellent corrosion resistance, heat resistance and mechanical properties.