Introduction to JIS G 3106 SM520 Structural Steel

JIS G 3106 SM520 is a structural steel grade specified by the Japanese Industrial Standards for use in welded structures such as bridges, buildings, ships, and storage tanks. It belongs to the family of rolled steels for welded structures, with medium strength and good weldability.
SM520 is typically available in three subgrades SM520A, SM520B, and SM520C, which differ slightly in terms of chemical composition and impact test requirements. These steels are characterized by a minimum yield strength of 355 MPa and tensile strength ranging from 490 to 610 MPa.
The steel offers good toughness and can be used in both low and medium temperature conditions. It is commonly supplied in hot-rolled plate form and is suitable for welding, forming, and machining processes.
Thanks to its balance of strength, ductility, and weldability, SM520 is a popular choice in civil and industrial engineering projects.