S275JR is a non-alloy, low-carbon structural steel grade defined under the European standard EN 10025-2. It is one of the most widely used steel grades in construction and engineering due to its balanced mechanical properties and cost-effectiveness.
Key Specifications
The designation "S275JR" provides a technical summary of the material's properties:
S: Indicates it is a Structural steel.
275: Specifies a minimum yield strength of 275 MPa (for thicknesses ≤ 16mm).
JR: Indicates a Charpy V-notch impact test requirement of at least 27 Joules at room temperature (+20°C).
Applications
S275JR is primarily used for manufacturing long and flat products for welded or riveted structures. Common uses include:
Construction: Beams, columns, and plates for buildings and bridges.
Engineering: Low-load machine parts like bushings, shafts, and axles.
Industry: Storage tanks, oil and gas platforms, and rail industry components.
Key Advantages
Weldability: Its low carbon content makes it exceptionally easy to weld using standard methods.
Machinability: Offers good machining performance similar to other mild steels.
Formability: Can be easily curved, folded, or cold-formed for various structural shapes.
The mechanical properties of S275JR are defined by the European standard EN 10025-2. The key values vary with product thickness, which is a critical design parameter.
Core Mechanical Properties (EN 10025-2):
| Property | Value Range | Notes |
|---|---|---|
| Yield Strength (ReH) min | 275 MPa – for nominal thickness ≤ 16 mm. 265 MPa – for >16 mm to 40 mm. 255 MPa – for >40 mm to 63 mm. 245 MPa – for >63 mm to 80 mm. 235 MPa – for >80 mm to 100 mm. |
Decreases with increasing thickness. |
| Tensile Strength (Rm) | 410 MPa to 560 MPa | Applies across all thickness ranges up to 100 mm. |
| Elongation at Fracture (A₅) min | 22 % – for thickness ≤ 40 mm (longitudinal test pieces). 20 % – for thickness >40 mm to 63 mm. 19 % – for thickness >63 mm to 100 mm. |
Measured on a gauge length of 5.65√S₀. Indicates ductility; decreases slightly with thickness. |
| Impact Toughness (KV) | Minimum 27 J at +20 °C | The "JR" designation mandates Charpy V-notch testing at room temperature. |
Additional Important Properties:
Density: Approximately 7.85 g/cm³.
Modulus of Elasticity (Young's Modulus): ~210 GPa.
Poisson's Ratio: ~0.3.
Shear Modulus: ~80 GPa.
Summary of Key Points:
Strength: S275JR is defined by its minimum yield strength of 275 MPa for common thin sections (≤16 mm), providing higher load capacity than S235 grades.
Ductility: Good elongation values (≥19-22%) ensure it can be formed and will deform plastically before fracture.
Toughness: The mandatory 27 J at +20°C impact test guarantees adequate resistance to brittle fracture under normal ambient conditions.
Thickness Dependency: Designers must use the correct yield strength value based on the specific thickness of the product being used, as it significantly affects safety calculations.
These properties make S275JR a reliable choice for general construction, frames, machinery, and infrastructure where higher strength than S235 is needed, but low-temperature service is not a requirement. For cold environments, grades like S275J0 or S275J2 (with toughness at 0°C or -20°C) should be selected.
1. What is S275JR steel?
S275JR is a non-alloy structural steel grade per EN 10025-2, with a minimum yield strength of 275 MPa and guaranteed impact toughness at room temperature (+20°C).
2. What is the yield strength of S275JR?
The minimum yield strength of S275JR is 275 MPa for material thickness up to 16 mm, decreasing slightly for thicker sections as per the standard.
3. What is the difference between S235JR and S275JR?
S275JR has a higher minimum yield strength (275 MPa vs. 235 MPa), providing greater load-bearing capacity for similar dimensions and applications.
4. What does the 'JR' mean in S275JR?
The 'JR' indicates that the steel is Charpy V-notch impact tested at +20°C with a minimum absorbed energy of 27 Joules, ensuring room temperature toughness.
5. Is S275JR equivalent to ASTM A36?
While close in strength, S275JR (275 MPa yield) is slightly stronger than standard A36 (250 MPa yield) and includes a mandatory impact test, so they are not direct equivalents.
6. What is S275JR used for?
It is widely used in general construction, structural frames, machinery components, bridges, and industrial applications requiring higher strength than S235 grades.
7. Can S275JR be welded?
Yes, S275JR offers good weldability using common methods like SMAW, MAG, or TIG, without requiring pre-heating under normal conditions and moderate thicknesses.
8. What is the chemical composition of S275JR?
Its composition typically includes max 0.21% C, max 1.50% Mn, and controlled limits for phosphorus and sulfur (e.g., P ≤ 0.035%, S ≤ 0.035%).
9. Is S275JR corrosion resistant?
No, S275JR is not corrosion-resistant. Like other carbon structural steels, it requires protective coatings such as painting or galvanizing for outdoor use.
10. What are the mechanical properties of S275JR?
Key properties include a yield strength ≥275 MPa (for t≤16mm), tensile strength of 410-560 MPa, and minimum elongation of 22-23% depending on thickness.
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.
