What does S275J2 mean?
S275J2 is a precise alphanumeric code from the European standard EN 10025-2 that tells you everything about the steel's key properties. It's a structured "data sheet" in a few characters.
S 275 J 2 – Decoded
1. S=Structural Steel
This simply designates that it is a structural steel, intended for load-bearing components in construction and engineering.
2. 275=Minimum Yield Strength
This is the most important number for a design engineer.
It means the steel has a minimum yield strength (ReH) of 275 Megapascals (MPa) for material thicknesses up to 16 mm.
Yield strength is the stress at which the material begins to deform permanently. It's the primary value used in structural calculations to prevent failure.
This minimum yield strength decreases slightly for thicker sections (e.g., >= 225 MPa for thicknesses over 63 mm).
3. J=Impact Toughness / Killed Steel
It signifies the steel is "Killed." This is a metallurgical term meaning it has been fully deoxidized during production. This results in a more uniform, homogeneous internal structure with fewer gas voids, leading to better and more consistent mechanical properties, especially in thicker sections.
It indicates that a specified impact toughness (Charpy V-notch test) is guaranteed.
4. 2=Test Temperature for Impact Toughness
This number specifies the temperature at which the impact toughness test is conducted.
'2' stands for -20℃. The number represents the test temperature in tens of degrees Celsius: 2=-20℃.
*So, a steel with 'J3' would be tested at -30℃, 'J0' at 0℃, etc.*
At this -20℃ temperature, the steel must absorb a minimum of 27 Joules of energy during the impact test without brittle fracture.
Putting It All Together: What S275J2 Guarantees
If you specify or receive material marked S275J2, you are guaranteed:
A Structural Steel for building frames, bridges, machinery, etc.
A Minimum Yield Strength of 275 MPa (for standard thicknesses).
Good Ductility and Weldability, due to its controlled chemical composition (max 0.20% Carbon).
A Homogeneous, Killed Steel microstructure.
Good Resistance to Brittle Fracture down to at least -20℃, making it suitable for structures in cold climates or subject to dynamic loads.
vs. S275JR:'R' means Rimmed steel (cheaper, less homogeneous, no guaranteed low-temperature toughness). S275JR is only tested at +20℃.
vs. S275JO:'0' means tested at 0℃. S275J2 has better low-temperature toughness.
vs. S355J2:'355' means a higher minimum yield strength (355 MPa). S355J2 is stronger but may have slightly different weldability.
Any application where a combination of good strength, reliable weldability, and guaranteed performance in cold weather is required.
In essence, S275J2 is a reliable, all-rounder structural steel defined by its 275 MPa strength and its certified ability to withstand impact loads at temperatures as low as -20℃.
1. What is the meaning of "J2" in S275J2?
The "J2" indicates the steel is fully killed (deoxidized) and has a specified impact toughness of at least 27 joules when tested at -20℃. The "J" denotes killed steel with guaranteed impact value, and the "2" specifies the test temperature (-20℃).
2. What is the yield strength of S275J2?
S275J2 has a minimum yield strength of 275 MPa (for material thickness <=16 mm). This strength value decreases slightly with increasing thickness, as specified in EN 10025-2.
3. Where is S275J2 commonly used?
It is widely used in general structural applications like building frames, bridges, and industrial platforms where moderate strength combined with good toughness in cold conditions (down to -20℃) is required.
4. How does S275J2 differ from S275JR?
The key difference is in toughness and deoxidation: S275JR is rimmed steel with impact tested only at +20℃, while S275J2 is killed steel with guaranteed impact value at -20℃, making it suitable for colder environments.
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff.
