SS400 is a Japanese standard carbon structural steel plate conforming to JIS G3101. It corresponds to Q235B in the Chinese national standard, with a tensile strength of 400 MPa. Due to its moderate carbon content, it offers well-balanced comprehensive properties, achieving good coordination between strength, ductility, and weldability, making it the most widely used grade.
Differences between Q235b Ss400:
Different Standards:
Q235B follows the Chinese National Standard (GB/T700-2006). “Q” denotes yield strength, ‘235’ indicates a minimum yield strength of 235 MPa, and “B” signifies the quality grade. SS400 follows the Japanese Industrial Standard (JIS G3101), where “SS” denotes structural steel and “400” indicates a tensile strength exceeding 400 MPa. In 16mm steel plate specimens, SS400 exhibits a yield strength 10 MPa higher than Q235A. Both tensile strength and elongation surpass those of Q235A.
Performance Characteristics:
In practical applications, both grades exhibit similar performance and are often sold and processed as ordinary carbon steel, with differences being less pronounced. However, from a standard definition perspective, Q235B emphasizes yield strength, while SS400 prioritizes tensile strength. For projects with detailed requirements for steel mechanical properties, selection should be based on specific needs.
Q235A steel plates have a narrower application range than SS400. SS400 is essentially equivalent to China's Q235 (equivalent to Q235A usage). However, specific indicators differ: Q235 specifies content limits for elements like C, Si, Mn, S, and P, while SS400 only requires S and P to be less than 0.050. Q235 has a yield strength exceeding 235 MPa, while SS400 achieves 245 MPa. SS400 (steel for general structure) denotes general structural steel with tensile strength exceeding 400 MPa. Q235 signifies ordinary carbon structural steel with a yield strength exceeding 235 MPa.
Applications of SS400: SS400 is commonly rolled into wire rods, round bars, square bars, flat bars, angle bars, I-beams, channel sections, window frame steel, and other structural shapes, as well as medium-thickness plates. It is extensively used in bridges, ships, vehicles, buildings, and engineering structures. It serves as reinforcing bars or for constructing factory roof trusses, high-voltage transmission towers, bridges, vehicles, boilers, containers, ships, etc. It is also widely employed for mechanical parts with less stringent performance requirements. Grade C and D steels can also be used for certain specialized applications.
Post time: Nov-01-2025
