When choosing structural steel for engineering projects, understanding the difference between S355J2 vs S355JR steel is critical. GNEE is a professional steel manufacturer and global supplier, specializing in EN 10025-2 structural steels for construction, offshore, and heavy engineering applications.
S355J2
Both S355J2 and S355JR are hot rolled non-alloy structural steels with similar strength levels, but their impact test requirements and service environments are significantly different.
This article explains their specifications, chemical composition, mechanical performance, and how to select the right grade for your project.
S355J2 vs S355JR Steel Standard and General Overview
S355J2 and S355JR steels are produced according to BS EN 10025-2, which covers hot rolled products of non-alloy structural steels.
Both grades share:
- Minimum yield strength of 355 MPa
- Comparable tensile strength range
- Similar alloying element limits
- Excellent weldability and formability
However, the key distinction lies in low-temperature impact performance, which directly affects application environments.
Difference Between S355J2 and S355JR Impact Test Requirements
The letter designations JR and J2 refer to Charpy V-notch impact test conditions.
S355JR steel
Impact test at +20°C
Suitable for normal structural environments
S355J2 steel
Mandatory impact test at –20°C
Designed for low-temperature or cold-region applications
Because of this requirement, S355J2 steel offers better toughness and crack resistance in cold or offshore environments.
Chemical Composition of S355J2 vs S355JR Steel
Both grades have very similar chemical compositions, with stricter phosphorus and sulfur limits for S355J2.
Chemical Composition (Heat Analysis, Max %)
| Standard | Grade | C | Mn | P | S | Si | N | Cu |
|---|---|---|---|---|---|---|---|---|
| EN 10025-2 | S355J2 | 0.20 | 1.60 | 0.025 | 0.025 | 0.55 | 0.012 | 0.55 |
| EN 10025-2 | S355JR | 0.24 | 1.60 | 0.035 | 0.035 | 0.55 | 0.012 | 0.55 |
Lower P and S content in S355J2 steel improves toughness and reduces brittle fracture risk.
Mechanical Properties of S355J2 vs S355JR Steel Plate and Sections
Mechanical Properties (Thickness ≤16mm)
| Grade | Yield Strength (MPa) | Tensile Strength (MPa) |
|---|---|---|
| S355J2 | ≥355 | 470–630 |
| S355JR | ≥355 | 470–630 |
From a strength perspective, both steels perform identically, making impact toughness the deciding factor rather than load-bearing capacity.
Size Range of S355 Structural Steel
Thickness: 3 mm – 200 mm
Width: up to 3,500 mm
Length: up to 18,000 mm
Custom cutting and machining services are available based on project drawings.
Applications of S355J2 vs S355JR Steel
S355JR Steel Applications
- Building structures
- Industrial workshops
- Bridges in mild climates
- Machinery frames
S355J2 Steel Applications
- Offshore platforms
- Marine engineering
- Wind power structures
- Cold-region and low-temperature projects
If your project involves low temperatures, high safety requirements, or offshore exposure, S355J2 is the recommended option.
Mill Test Certificates and Quality Control
All S355J2 and S355JR materials supplied by GNEE are delivered with mill test certificates in compliance with:
EN 10204 2.1
EN 10204 2.2
EN 10204 3.1
EN 10204 3.2 (with third-party inspection)
Third-party inspections supported:
SGS
BV
Lloyd's Register
In summary, while S355J2 vs S355JR steel share similar chemical composition and mechanical strength, their impact toughness and service temperature requirements make them suitable for very different applications.
Choosing the correct grade ensures long-term safety, durability, and compliance with engineering standards.
What material is S355J2?
S355J2 is a medium tensile, low carbon manganese steel which is readily weldable and possess good impact resistance (also in sub-zero temperatures). This material is commonly supplied in the untreated or normalized condition. Machinability of this material is similar to that of mild steel.
What is the difference between S355JR and S355J2?
S355JR steel has a minimum impact strength of 27 J under 20-degree temperature conditions while the second type of steel, S355J2+N has the same impact strength but with a temperature of -20 degrees.
What is the equivalent of S355J2 in China?
EN10025 S355J2 equivalent grade in China is Q345D. Their chemical composition is slightly different and mechanical properties are similar.
Is S355J2 N mild steel?
As an unalloyed low Carbon Steel Plates mild steel grade S355 is supplied in the hot rolled condition. The S355 steel specifications are high yield non alloy steels. First specified in the European EN10025 standard and later published by the British Standards Institure (BSI) as BS EN 10025 S355, S355J2 and S355J2+N.