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S355JR vs ASTM A36: Key Differences and How to Choose the Right Structural Steel

1.What is S355JR and ASTM A36?

S355JR STEEL vs A36 STEEL:

S355JR and ASTM A36 are the two most popular types of structural steel which are used widely in the world for construction applications.

S355JR is a grade of EN 10025, whereas ASTM A36 is the grade for ASTM, which are the most recognized standards in the United States as well as some other parts of the world. Both grades can be found in similar structural applications, but the philosophy behind design, testing requirements, and mechanical performance are very different.

2. Comparison of mechanical properties

Property S355JR (EN 10025) ASTM A36
Minimum Yield Strength 355 MPa 250 MPa
Tensile Strength 470–630 MPa 400–550 MPa
Impact Test Required (JR: 20°C) Not mandatory
Weldability Very good Good

The biggest difference is the yield strength.

The yield strength of S355JR is about 40% greater than the yield strength of ASTM A36 which means that the structural sections can be made lighter or that the loads can be increased.

3. Impact Toughness and Structural Safety

S355JR includes compulsory Charpy impact testing (JR grade at +20°C), which gives predictable toughness performance under dynamic loading conditions.
There is no requirement for any impact testing for ASTM A36, unless the buyer states so in the purchase order.
To be used for: dynamic loads vibration moderate temperature variations For use in dynamic loading applications.
S355JR has more guarantees to reliability.

4. Typical Applications

S355JR

  • Bridges and overpasses

  • High-rise buildings

  • Industrial platforms

  • Heavy machinery frames

ASTM A36

  • Low-rise buildings

  • General fabrication

  • Base plates and brackets

  • Non-critical load-bearing structures

5. How to decide between S355JR and A36?

S355JR is a better choice if:

Reducing structure weight is important
Safety margins may be higher
They was subject to EN standards in the project

Opt for ASTM A36 if:

Price is most important
Loads are very light
Be ASTM compliant."

6. Common Mistakes to Avoid

Assuming S355JR and A36 are direct equivalents

Ignoring impact toughness requirements

Using A36 in fatigue-sensitive structures

S355JR and ASTM A36 serve similar purposes, but they are not interchangeable without engineering evaluation.

ROYAL GROUP

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Kangsheng development industry zone,
Wuqing district, Tianjin city, China.

E-mail

sales01@royalsteelgroup.com

Phone

Sales Manager: +8613652091506

Hours

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Post time: Jan-09-2026