ST37-2 vs S235JR Steel Plate

ST37-2 and S235JR are two of the most commonly referenced structural steel grades in the European and international steel markets. Many buyers encounter both designations when sourcing steel plates and often wonder whether they are the same material. While the two grades are very similar and are frequently considered equivalents, there are some important differences that should be understood.
ST37-2 is a structural steel grade specified under the former German standard DIN 17100, while S235JR is defined by the modern European standard EN 10025-2. When the DIN standards were replaced by European harmonized standards, S235JR became the direct successor to ST37-2 for most structural applications.
The naming systems reflect different standard philosophies. In ST37-2, "ST" stands for structural steel, while "37" refers to the approximate tensile strength class. In contrast, S235JR uses the European designation system, where "S" represents structural steel and "235" indicates a minimum yield strength of 235 MPa. The suffix "JR" signifies that the material meets a specified impact test requirement at room temperature.
In terms of chemical composition, both grades are low-carbon structural steels with excellent weldability and formability. The carbon content is generally below 0.20%, allowing easy welding, bending, cutting, and fabrication. While there may be slight differences in chemical limits between the two standards, these differences are usually not significant in practical applications.
The mechanical properties of ST37-2 and S235JR are also very similar. Both grades typically provide a minimum yield strength of 235 MPa and a tensile strength ranging from approximately 360 MPa to 510 MPa. This makes them suitable for a wide variety of structural and engineering applications where moderate strength and good toughness are required.
Both materials are commonly used in steel structures, industrial buildings, bridges, storage tanks, machinery frames, transportation equipment, and general fabrication projects. Their excellent processing characteristics and competitive cost make them popular choices worldwide.
For buyers, the most important consideration is project specification compliance. European projects usually require S235JR certification according to EN 10025 standards, while some older drawings, technical documents, or replacement projects may still specify ST37-2. Therefore, suppliers should provide clear material equivalency documentation and appropriate test certificates.
In conclusion, ST37-2 and S235JR steel plates are extremely similar in composition, mechanical properties, and applications. S235JR is essentially the modern European replacement for ST37-2, making the two grades interchangeable in many structural steel projects when proper certification requirements are met.