ASTMA228 spring steel is hardened and tempered condition due to the elastic, and specifically for the manufacture of springs and elastic components of steel. Elasticity of steel depends on the elastic deformation capacity, that is within the predetermined range, the elastic deformation capacity to withstand a certain load, the load does not occur after the removal of permanent deformation. Spring steel should have excellent overall performance, such as mechanical properties (especially elastic limit, ultimate strength, yield ratio), reduced ballistic performance (ie, decreased resistance to elastic properties, also known as sag resistance), fatigue properties, hardenability physical and chemical properties (heat resistance, low temperature, oxidation, corrosion, etc.). To meet these performance requirements, the spring steel has excellent metallurgical quality (high purity and homogeneity), good surface quality (strict control of surface defects and decarburization), the exact shape and size. According to GB/T13304 "steel classification criteria," according to the basic performance and usage characteristics, spring steel belongs to the mechanical structural steel; according to quality grade, is a special quality steel, that in the production process requires strict control of quality and performance special steels. According to China's habit, spring steel is a special steel. ASTMA228 spring steel is hardened and tempered condition due to the elastic, and specifically for the manufacture of springs and elastic components of steel. Elasticity of steel depends on the elastic deformation capacity, that is within the predetermined range, the elastic deformation capacity to withstand a certain load, the load does not occur after the removal of permanent deformation. Spring steel should have excellent overall performance, such as mechanical properties (especially elastic limit, ultimate strength, yield ratio), reduced ballistic performance (ie, decreased resistance to elastic properties, also known as sag resistance), fatigue properties, hardenability physical and chemical properties (heat resistance, low temperature, oxidation, corrosion, etc.). To meet these performance requirements, the spring steel has excellent metallurgical quality (high purity and homogeneity), good surface quality (strict control of surface defects and decarburization), the exact shape and size. According to GB/T13304 "steel classification criteria," according to the basic performance and usage characteristics, spring steel belongs to the mechanical structural steel; according to quality grade, is a special quality steel, that in the production process requires strict control of quality and performance special steels. According to China's habit, spring steel is a special steel.