What are the Differences Between S355J0, S355J2, and S355JR? A Complete Guide to Chemical Properties, Impact Energy, and Application Scenarios

In communications with global customers, we are frequently asked: “What exactly are the differences between S355J0, S355J2, and S355JR?” This is not just a question about material designations, but a key distinction related to structural safety, low-temperature toughness, weldability, and engineering service life.

As LONGMA, with over 20 years of experience in steel pipe and structural steel production, we will clarify the core differences between the three based on authoritative standards (EN 10025-2, ASTM A370, ASTM E23) and combined with internal laboratory test data, and provide material selection recommendations based on engineering procurement risks.

Designation Meanings and Core Differences

Table 1: Definitions and Impact Energy Requirements for S355JR / S355J0 / S355J2

The above differences are the core points of the difference between s355jr and s355j0, as well as the most critical basis for engineers to judge s355j0 vs s355j2 and unterschied s355j0 und s355j2.

Chemical Composition Comparison (Weldability is Mainly Determined by This)

The standard chemical composition ranges of the three are almost identical. The main purposes of structural steel are as follows:

• Low carbon content ensures weldability
• Adjust strength and toughness through Mn and Si
• Control P and S to obtain good resistance to brittle fracture

Table 2: Typical Chemical Composition (mass fraction %)

It can be seen from the above that chemical composition is not the main difference between S355J0 vs S355JR and S355JR vs S355J2; the real key lies in the different impact energy grades.

Mechanical Properties (Same Yield Strength, Different Toughness Grades)

Table 3: Typical Mechanical Properties (thickness ≤ 16 mm)

This is the real distinction behind difference between s355jr and s355j0 / s355jr vs s355j2.

Why is Impact Energy Important? How to Test Correctly According to Standards?

1. Why Does Impact Energy Affect Engineering Safety?

The toughness of steel decreases at low temperatures. If the material is subjected to impact loads in a low-temperature environment, brittle fracture may occur. Therefore:

• For projects in cold regions → choose J2
• For projects with a minimum temperature of 0°C → choose J0
• For projects always at room temperature → choose JR

This is why s355j0 vs s355j2 is frequently compared in engineering projects.

2. Impact Test Standards and Implementation Process (Must Be Specified in Procurement Contracts)

Common Standards:

• ASTM E23: Standard Test Methods for Notched Bar Impact Testing of Metallic Materials
• ASTM A370: Standard Test Methods and Definitions for Mechanical Testing of Steel Products (including impact testing)

Key Test Requirements (Must-read for Engineering Procurement):

• Specimen orientation: Longitudinal sampling
• Three specimens per group, with the average value used for judgment
• Strictly control the impact temperature (+20°C / 0°C / −20°C)
• Results must correspond to heat numbers and batch numbers to ensure traceability

In the material requirements of engineering specifications, it should be clearly written as:

“S355J2, Charpy V-notch 27J @ −20°C, tested per ASTM E23 / ASTM A370.”

Application Scenario Comparison (Provide Accurate Material Selection Recommendations for Engineering)

Table 4: Typical Engineering Application Scenarios of the Three

Therefore, when customers ask:

• s355j0 vs s355jrwhich is better?

 If the temperature is close to freezing point, S355J0 is recommended.

• s355jr vs s355j2which is safer?

 If the temperature ≤ −10°C → S355J2 must be selected.

• unterschied s355j0 und s355j2?

 Different toughness grades and applicable temperatures: S355J2 must be used for −20°C scenarios.

Procurement and Quality Control Recommendations (Reduce Engineering Risks)

Based on over 20 years of experience, LONGMA recommends that purchasers must specify the following 5 requirements:

1. Clearly mark the sub-grade and impact temperature

e.g.: S355J2, 27J @ −20°C

Prevent suppliers from passing off JR or J0 as J2.

2. Request three original impact test reports (including heat number and batch number)
3. Require tensile tests to be performed in accordance with ASTM A370
4. Retain samples for key batches for third-party arbitration inspection (BV / SGS / TUV)
5. Request OES spectrometer data of chemical composition to ensure stable weldability

LONGMA Internal Laboratory: Your Most Reliable Quality Assurance

LONGMA is equipped with a complete internal laboratory, including:

• OES spectral chemical analysis
• Tensile testing (ASTM A370)
• Charpy impact testing (ASTM E23)
• Full-process metallographic inspection, hardness inspection, and dimension testing

All ex-factory batches are accompanied by complete inspection records, and data is retained to be traceable to the heat number and batch number of each steel pipe.

This is more trustworthy to engineering contractors, government acceptance authorities, and owners than a simple certificate of conformity.

Conclusion: What are the Core Differences Between the Three?

If You Need, We Can Provide:

• Real S355J0 / J2 / JR inspection report samples
• Technical specifications (Tech Spec) available for bidding
• Material selection plans recommended according to project environment
• Free samples and third-party testing support

Welcome to contact LONGMA —— Use real test data to escort every one of your engineering projects.