Understanding S355 Steel Grades

Expert Guide: S355JR vs S355J2 vs S355J2+N

Introduction to S355 Steel

When it comes to structural steel, the S355 family (EN 10025 standard) stands out as one of the most trusted materials worldwide. Known for its 355 MPa minimum yield strength, excellent weldability, and versatility, S355 steel is widely used in construction, offshore engineering, shipbuilding, bridges, pipelines, and heavy machinery.

However, buyers and engineers often face a common dilemma:

What's the difference between S355JR,S355J2, and S355J2+N ?

Making the right choice is critical because the wrong grade can compromise safety, durability, and cost-efficiency.

What is S355 Steel?

High Strength

355 MPa minimum yield strength, stronger than S275 or mild steel (ASTM A36).

Excellent Workability

Superior weldability and machinability for diverse applications.

Global Availability

Available in plates, sheets, round bars, pipes, and hollow sections worldwide.

Grade Comparison

S355JR Steel

"JR" = impact tested at +25°C. Standard impact resistance for general environments.

Properties: Yield strength ≥ 355 MPa, tensile strength 470–630 MPa.

Applications: Residential & commercial construction, standard steel frameworks.

S355J2 Steel

"J2" = impact tested at -20°C. Improved toughness in low temperatures.

Applications: Bridges, offshore structures, heavy equipment in cold regions.

S355J2+N Steel

"+N" = Normalized condition for refined grain structure and superior toughness.

Applications: Critical structures like oil rigs, wind energy towers, defense vehicles.

Property	S355JR (+20°C)	S355J2 (-20°C)	S355J2+N (-20°C)
Impact Test Temp	+20°C	-20°C	-20°C (Normalized)
Yield Strength	355 MPa	355 MPa	355 MPa
Toughness	Standard	Higher	Highest
Processing	As-rolled	As-rolled	Normalized
Applications	General use	Cold climates	Critical projects

Real-World Applications

S355JR Applications

Residential & commercial construction, urban infrastructure, frameworks, and automotive parts.

S355J2 grade applications in bridge engineering

S355J2 Applications

Bridges, pipelines, mining machinery, offshore oil platforms, and cold-region projects.

S355J2+N grade marine engineering projects

S355J2+N Applications

Oil & gas rigs, marine engineering, wind energy towers, defense vehicles, and heavy structural projects.

Frequently Asked Questions

What is the difference between S355JR and S355J2?

The main difference is impact resistance: S355JR is tested at +20°C, while S355J2 is tested at -20°C, making J2 better for colder climates.

Is S355J2+N stronger than S355JR?

Yes. While both have the same yield strength (355 MPa), S355J2+N is normalized, offering superior toughness and consistency for critical applications.