Both S355J2 channel steel and S275JR channel bar are manufactured in accordance with the European standard EN 10025-2 and belong to non-alloy structural steels.
While they share similar manufacturing standards and applications, there are significant differences in strength level and low-temperature performance, which directly affect material selection in engineering projects.
Basic Differences Overview
Strength Level:
S355J2 channel steel offers higher yield and tensile strength than S275JR channel bar, making it suitable for heavier load-bearing structures.
Low-Temperature Impact Requirement:
S355J2 must pass a Charpy V-notch impact test at −20°C, ensuring reliable toughness in cold environments.
S275JR, however, does not require a low-temperature impact test at −20°C and is generally intended for normal temperature applications.
Service Environment:
S355J2: Suitable for cold climates (down to −20°C)
S275JR: Recommended for mild or room-temperature conditions
Certification & Available Stock
All S355J2 channel steels and S275JR channel bars are supplied with EN 10204 3.1 Mill Test Certificates, ensuring full traceability of chemical composition and mechanical properties.
Typical Stock Sizes Include:
UPN Channel Steel (Tapered Flanges):
UPN 100 × 50 × 6 × 8.5
UPN 120 × 55 × 7 × 9
UPN 200 × 75 × 8.5 × 11.5
UPE Channel Steel (Parallel Flanges):
UPE 80 × 50 × 4 × 7
UPE 120 × 60 × 5 × 8
UPE 140 × 65 × 5 × 9
UPE 220 × 85 × 6.5 × 12
Chemical Composition Comparison
Heat Analysis, Max %
| Standard | Grade | C | Mn | P | S | Si | Cu | N |
|---|---|---|---|---|---|---|---|---|
| EN 10025-2 | S275JR | 0.21 | 1.50 | 0.035 | 0.035 | – | 0.55 | 0.012 |
| EN 10025-2 | S355J2 | 0.20 | 1.60 | 0.025 | 0.025 | 0.55 | 0.55 | – |
Mechanical Properties Comparison
(Nominal Thickness ≤16 mm)
| Standard | Grade | Minimum Yield Strength (MPa) | Tensile Strength (MPa) |
|---|---|---|---|
| EN 10025-2 | S275JR | 275 | 410–560 |
| EN 10025-2 | S355J2 | 355 | 470–630 |
Application Recommendations
| Application Scenario | Recommended Grade |
|---|---|
| General construction, indoor structures | S275JR |
| Load-bearing structures | S355J2 |
| Cold climate or outdoor structures | S355J2 |
| Cost-sensitive, non-critical use | S275JR |
S355J2 channel steel provides higher strength and guaranteed toughness at −20°C, making it suitable for cold regions and high-safety structures.
S275JR channel bar is a cost-effective choice for standard structural applications under normal temperature conditions.
Clear specification of steel grade, impact requirement, and certification (EN 10204 3.1) is essential during procurement to avoid performance risks.
What is S355JR Channel Steel?
S355JR Channel Steel is a structural steel profile conforming to EN 10025-2 with a minimum yield strength of 355 MPa. The "JR" designation indicates it is impact tested at 20°C, making it suitable for general structural applications in moderate-temperature environments. Channel steel is widely used in building frameworks, industrial sheds, bridges, and heavy machinery components.
What are the mechanical properties of S355JR Channel Steel?
S355JR Channel Steel provides a minimum yield strength of 355 MPa and a tensile strength ranging from 470 to 630 MPa, depending on the section and thickness. It has good ductility, allowing it to absorb stresses without sudden failure, and exhibits reliable toughness suitable for welded and fabricated structures.
How does S355JR Channel Steel perform under welding?
Due to its low carbon equivalent, S355JR Channel Steel is easily weldable using standard welding processes such as SMAW, GMAW, or FCAW. However, for thicker sections or highly restrained joints, controlling heat input and following proper welding procedures is recommended to prevent residual stress buildup or softening in the heat-affected zone (HAZ).
Why is impact toughness important for S355JR Channel Steel?
Impact toughness prevents brittle fracture under dynamic or sudden loads. S355JR has been tested at 20°C to ensure it can withstand normal operational stresses. For projects in colder climates, other grades like S355J0 or S355J2 may be selected for lower-temperature impact requirements.
How does S355JR Channel Steel compare with other structural steels?
Compared with S275JR, S355JR offers higher yield strength, allowing lighter sections and reduced material usage while maintaining structural integrity. Compared to high-strength quenched-and-tempered steels like S690, S355JR is easier to fabricate and weld, though it has lower maximum strength, making it more cost-effective for general construction applications.
What are the typical applications of S355JR Channel Steel?
S355JR Channel Steel is commonly used in building frames, bridges, industrial equipment, machinery bases, and infrastructure projects. Its combination of strength, weldability, and toughness ensures safety and durability in a wide range of structural and engineering applications.