What the S235 Grade Family Covers
S235 is the basic structural steel grade of EN 10025-2, with a minimum yield strength of 235 MPa for thickness up to 16 mm. The suffixes JR, J0 and J2 define the Charpy impact requirement, not the strength: JR guarantees 27 J at 20 degrees Celsius, J0 at 0 degrees Celsius and J2 at minus 20 degrees Celsius. The angle bar section itself is identical across the three variants.
For most indoor and temperate-climate structures S235JR is sufficient. J0 and J2 are specified for colder environments, dynamic loading and welded connections subject to fatigue.
Equivalent Grades in Other Standards
S235 corresponds to a well-known family of grades around the world:
St37-2 per DIN 17100, the former German designation of the same steel.
A36 per ASTM A36, the standard US structural carbon steel.
SA283GrA per ASTM A283, a low and intermediate tensile strength carbon plate grade.
SM400A per JIS G3106, the Japanese rolled steel for welded structure.
Q235 per GB/T 700, the Chinese carbon structural steel.
Q255 and Q275 per GB/T 700, slightly higher strength Chinese grades.
These grades are broadly interchangeable for general structural work, but the governing contract standard should be followed for testing and certification.
Mechanical Properties
S235JR, S235J0 and S235J2 all provide a minimum yield strength of 235 MPa up to 16 mm, 225 MPa for 16 to 40 mm, and a tensile range of 360 to 510 MPa. The carbon content is limited to 0.17 percent for J2, giving better weldability and toughness at low temperature.
Angle Bar Forms and Sizes
Equal and unequal angles are available in the full hot rolled range, from 20 x 20 x 3 mm to 200 x 200 x 24 mm. Sizes such as 50 x 50 x 5, 75 x 75 x 6 and 100 x 100 x 10 are standard stock items, and angles can be cut, drilled, punched or galvanized to order.
Selection and Delivery
Choose S235JR for general building steelwork, S235J0 for outdoor structures in cold regions and S235J2 for welded structures where the ambient temperature can fall below 0 degrees Celsius. Mill certificates state the heat number, chemical composition, yield, tensile and impact results. Bundles are marked with grade and heat for full traceability.
Frequently Asked Questions
Q: What is the difference between S235JR, S235J0 and S235J2?
Only the guaranteed impact temperature differs: JR at 20 degrees Celsius, J0 at 0 degrees Celsius and J2 at minus 20 degrees Celsius, all with 27 J minimum.
Q: Is St37-2 the same steel as S235JR?
Yes, St37-2 from the old DIN 17100 standard corresponds to S235JR in EN 10025-2, and the two names are treated as equivalents.
Q: Can S235 be supplied as unequal angles?
Yes, equal and unequal angles are both rolled in the S235 grades.
Q: Which grade is best for welded outdoor structures?
S235J2 is preferred for welded outdoor structures in cold climates because its impact performance is guaranteed at minus 20 degrees Celsius.
Q: What certificates are issued with S235 angles?
EN 10204 type 3.1 mill certificates are provided, showing the heat analysis and mechanical test results.