Japanese Standard (1)

 　　In the grades of Japanese steel (JIS series), ordinary structural steel mainly consists of three parts to represent the material.

　　For example, S (Steel) represents steel, F (Ferrim) represents iron; The second part represents different shapes, types, and uses, such as P (Plate) for plates, T (Tube) for tubes, and K (Kogu) for tools; The third part represents the characteristic number, which is generally the tensile strength. For example, SS400 represents Steel, the second S represents Structure, 400 represents the lower limit tensile strength of 400MPa, and the overall represents ordinary structural steel with a tensile strength of 400MPa.