S355JR vs S355J2 vs S355NL: Key Differences, Impact Test & Equivalent Materials

S355JR vs S355J2 vs S355NL – Key Differences Explained

S355JR, S355J2, and S355NL differ mainly in impact test temperature and low-temperature performance, which directly determine where each grade can be safely used.

For most engineering and procurement decisions, the key question is simple:

• S355JR → suitable for +20°C environments
• S355J2 → suitable for –20°C conditions
• S355NL → suitable for –50°C and critical low-temperature applications

Choosing the wrong grade can lead to brittle fracture risks in cold environments, so understanding these differences is essential for structural safety and compliance.

Quick Comparison: S355JR vs S355J2 vs S355NL

Grado	Límite elástico (MPa)	Prueba de impacto	Temperatura	Condición	Uso típico
S355JR	≥355	27J	+20°C	Como rodado	Estructuras estándar
S355J2	≥355	27J	-20°C	Como rodado	Puentes, regiones frías
S355NL	≥355	27J	-50°C	Normalizado / Normalizado Laminado	Offshore, equipos de baja temperatura

For a broader comparison of EN structural steels, see our guide: Comparación y propiedades del acero estructural S235 / S275 / S355.

S355JR vs S355J2 vs S355NL Equivalent Materials (ASTM / JIS / GB)

For global sourcing, equivalent material comparison is a key concern.

Grado EN	Equivalente ASTM	JIS	GB
S355JR	ASTM A572 Gr 50	SM490A	Q345B
S355J2	ASTM A572 Gr 50 / A992	SM490B	Q345D
S355NL	ASTM A516 Gr 70 (approx., toughness differs)	SM490C	Q345E

⚠️ Important:
Se trata de reference equivalents, not exact substitutions.

• ASTM A516 Gr 70 differs in pressure vessel application
• Toughness requirements must always be verified
• Welding and thickness may affect substitution decisions

👉 In procurement, always confirm:

• project standards
• impact test requirements
• delivery condition (+N / normalized)

Impact Test Temperature: The Core Difference

Al comparar S355JR vs S355J2 vs S355NL, the most critical factor is Charpy V-notch impact testing:

• S355JR: tested at +20°C → no guarantee in cold climates
• S355J2: tested at -20°C → suitable for outdoor and winter conditions
• S355NL: tested at -50°C → designed for extreme environments

This is why:

• S355NL is required for offshore, wind towers, and low-temperature equipment
• S355JR cannot replace S355J2 in cold regions
• S355J2 is the standard choice for bridges in Europe

S355J2 vs S355NL: What’s the Real Difference?

Many buyers compare S355J2 vs S355NL for low-temperature projects.

Key differences:

• S355J2 → –20°C toughness
• S355NL → –50°C toughness
• S355NL → delivered in normalized condition (+N)
• S355NL → better performance in thick plates and critical welding structures

Conclusion:

• Utilice S355J2 for general cold regions
• Utilice S355NL for offshore, wind power, or extreme climates

S355JR vs S355J2: Can You Substitute?

This is one of the most common procurement questions.

Short answer:

• ✔️ Possible in warm environments
• ❌ Not recommended in cold conditions

¿Por qué?

• S355JR has no low-temperature guarantee
• S355J2 ensures toughness at –20°C

👉 Rule of thumb:
If your structure is exposed to outdoor winter conditions,
S355J2 is the safer and widely accepted choice.

How to Choose Between S355JR vs S355J2 vs S355NL

Selection should always be based on service temperature and safety requirements:

• S355JR → Standard climate, cost-effective
  For warm/Mediterranean regions or indoor structures.
• S355J2 → Cold regions, bridges, better toughness
  Safe at –20°C; widely used in EU bridge fabrication.
• S355NL → Offshore, wind power, cryogenic conditions
  Normalized delivery ensures reliable toughness at –50°C.

In international projects, S355J2 is the most commonly specified grade, while S355NL is used when safety margins are critical.

Aplicaciones del acero S355JR / S355J2 / S355NL en proyectos de construcción y offshore

Estas calidades se suministran en chapa, bobina, barra redonda y tubo utilizados en múltiples sectores:

• S355JR – general construction, machinery
  For buyers looking for materials in this grade, explore S355JR Carbon Steel Plate, S355JR Carbon Steel Coil y S355JR Round Steel Bar.
• S355J2 / S355NL – Bridges & Cold-Region Projects
  If your project requires plates for bridge, wind tower, or heavy-duty structural fabrication, you can review the Placa de torre eólica section for available S355J2/S355NL options.

FAQs: S355JR vs S355J2 vs S355NL (For Buyers & Engineers)

1. What is the main difference between S355JR and S355J2?

The difference is impact test temperature: S355JR is tested at +20°C, while S355J2 is tested at –20°C.

2. What is the S355JR equivalent to ASTM?

The most common ASTM equivalent for S355JR is ASTM A572 Grado 50, widely used for general structural applications.

3. What is the S355J2 equivalent to ASTM?

S355J2 is commonly compared with ASTM A572 Grado 50 o ASTM A992 in structural applications. However, exact substitution should be verified based on impact toughness and chemical composition.

4. What is the S355NL equivalent material?

S355NL is often referenced against ASTM A516 Grado 70 o A572 Grado 50 for low-temperature plate applications, though its fine-grain and normalized condition set it apart.

5. Can S355JR replace S355J2?

S355JR can replace S355J2 only in projects that do not require low-temperature impact toughness. For outdoor structures in cold climates or components exposed to winter temperatures, S355J2 remains the safer choice.

6. S355JR vs S355NL: What’s the difference?

S355NL offers superior low-temperature toughness (-50°C) and is delivered in a normalized condition, making it suitable for offshore, pressure equipment, and heavily welded structures. S355JR is intended for standard structural applications without low-temperature requirements.

7. Is S355J2 better than S355JR?

Neither grade is universally “better.” S355J2 is preferable for colder climates due to its –20°C impact toughness, while S355JR is a cost-efficient choice for general construction in moderate environments.

8. S355J2 vs S355NL: Which one should I choose?

S355J2 is suitable for general heavy structures requiring –20°C impact toughness, while S355NL is preferred for offshore, wind energy, or low-temperature pressure equipment due to its –50°C toughness and normalized delivery.

9. Is S355JR equivalent to A572 Grade 50?

Yes. For many structural applications, S355JR is considered comparable to ASTM A572 Grade 50 due to similar strength and composition.

10. What does S355J2+N mean?

S355J2+N indicates S355J2 steel delivered in a normalized condition (+N).
Normalizing improves grain structure, toughness, and weldability compared with standard as-rolled S355J2.

In international procurement, S355J2+N equivalent material is often compared with ASTM A572 Grade 50 or ASTM A516 Grade 70 depending on toughness requirements.

Still unsure which S355 grade best suits your project?

Acero CJM suministra placas y bobinas S355JR, S355J2 y S355NL a compradores de todo el mundo.
Contacte con nuestro equipo de ingenieros para la selección personalizada de materiales y el apoyo al suministro.