ss400 is a Japanese steel marking material, the equivalent of the domestic Q235 steel. Foreign standard structural steel often classified according to tensile strength, such as SS400 (Japan is so marked), where the minimum value of 400 means that σb to 400MPa high strength steel is σb ≥ 1373 Mpa steel.

SS400 is basically the same with our Q235 (equivalent Q235A use). However, the difference in specific indicators, Q235 on C, Si, Mn, S, P and other elements of content have made a request, but only requires SS400 S, P less than 0.050. Q235 is greater than the yield point 235 MPa, while the yield point of SS400 245MPa. SS400 (steel for general structure), which means that the general structure of 400MPa tensile strength greater than steel. Q235 is greater than the yield point of 235MPa meaning of ordinary carbon steel. SS400 Standard No. JIS G3101-1995. Q235 standard number GB/T700-2006.