S355J2 Steel: Properties, S355JR Comparison and Supply

S355J2 is a high-strength, non-alloy structural steel defined in the EN 10025-2 standard. Its material number is 1.0577, and it is considered the current equivalent of the St52-3 grade in the former DIN standard. Thanks to its impact toughness at low temperatures, it is widely used in demanding applications such as steel construction, bridges, cranes, construction machinery and wind energy. In this article, you will find the technical properties of S355J2, how it differs from S355JR and what to consider when purchasing it.

What does the S355J2 designation mean?

Each letter and number in the grade name S355J2 indicates a specific property of the steel:

• S: Structural steel
• 355: Minimum yield strength of 355 MPa for the smallest thickness group (≤16 mm)
• J2: Minimum impact energy of 27 J at -20 °C in the Charpy impact test

Other grades in the same family are distinguished by impact test temperature: S355JR provides 27 J at +20 °C, S355J0 at 0 °C and S355J2 at -20 °C, while S355K2 provides 40 J at -20 °C. The delivery condition is usually specified as +N (normalized or normalized rolled) or +AR (as rolled), which is why S355J2+N is a common designation.

S355J2 chemical composition

Heat analysis according to EN 10025-2 (for thickness ≤16 mm, maximum values):

The carbon content may increase slightly as thickness increases. The carbon equivalent value (CEV) is a maximum of 0.45 for thicknesses up to 30 mm, which gives S355J2 good weldability.

S355J2 mechanical properties

The main mechanical properties of S355J2 according to EN 10025-2 are:

The minimum yield strength gradually decreases as thickness increases. When performing design calculations for thick-section parts, the values for the relevant thickness group should be used.

Difference between S355J2 and S355JR

Both grades have the same yield and tensile strength. The main difference is the temperature at which impact toughness is guaranteed, along with the correspondingly tighter phosphorus and sulfur limits.

If your structure will operate in a cold climate, outdoors or under dynamic loads such as vibration and impact, S355J2 is the safer choice. For indoor and statically loaded applications, S355JR is usually sufficient. You can find a detailed look at the differences between S235 and S355 grades in our article S235 (St37) vs. S355 (St52) Steel Comparison.

S355J2 applications

Typical applications of S355J2 include:

• Steel construction, bridges and industrial structures
• Cranes, lifting equipment and construction machinery chassis
• Wind turbine towers and connection components
• Trailers, semi-trailers and vehicle bodies
• Non-pressurized tanks and silos
• Machine frames and heavily loaded welded fabrications

S355J2 international equivalents

Grades equivalent to S355J2 in different standards are as follows:

International equivalents are not identical in terms of chemical composition and test conditions; for critical applications, certificate values should be the basis for decisions.

What to consider when buying S355J2

• Delivery condition: Specify +N or +AR.
• Yield strength: Check the minimum yield strength for your thickness group.
• Certification: Request an EN 10204 3.1 certificate that includes impact test results.
• Section and tolerance: Clarify the flat, round, square or hexagon section and the dimensional tolerance.
• Carbon equivalent: If welded fabrication is planned, verify the CEV value on the certificate.

S355J2 delivery conditions: +N vs. +AR

Under EN 10025-2, S355J2 can be delivered in the as-rolled (+AR) or normalized / normalized rolled (+N) condition. In the +N condition, the material has been formed at normalizing temperature or normalized afterwards, giving it a more uniform, fine-grained structure. For parts that will undergo subsequent hot forming or normalizing, the +N delivery condition is preferred to preserve mechanical properties. For standard construction applications, the +AR condition is usually sufficient. Specifying the delivery condition in your request for quotation also makes it easier to compare certificates and prices.

In which forms is S355J2 supplied?

In addition to sheet and plate, S355J2 grade steel is also used in long product forms such as flat, square, round and hexagon bars. Dimensional and shape tolerances are determined according to EN 10058–10061 for hot rolled bars and EN 10278 for cold drawn bars. In machine building, S355J2 round bars are frequently used for pins, bushings, joints and welded shaft applications. S355J2 in flat bar form is used for connection plates, lugs and chassis reinforcements.

Practical notes on welding

• Surface cleanliness: Mill scale, rust and oil should be removed from the surface before welding.
• Preheating: The need for preheating should be evaluated for thick sections and low ambient temperatures.
• Consumables: Using low-hydrogen electrodes and wire reduces the risk of cold cracking.
• Procedure: For structures under dynamic loads, working with a welding procedure specification (WPS) is recommended.

S355 grade steel supply from Uyar Çelik

Uyar Çelik supplies structural and engineering steels such as S355JR, S235JR, S275JR, E295, E335 and E360 in flat, square, round and hexagon sections. For grades with special impact requirements such as S355J2, you can share your requirements with our sales team to get up-to-date stock and lead time information.

Frequently asked questions

Are S355J2 and St52 the same?

S355J2 is the EN 10025-2 equivalent of the St52-3 grade in the former DIN standard. The term “St52” is still widely used on the market.

Can S355J2 be welded?

Yes. Thanks to its low carbon equivalent, S355J2 has good weldability. For thick sections, whether preheating is required should be determined by the welding procedure.

What is the material number of S355J2?

The material number of S355J2 is 1.0577.

Conclusion

With impact toughness guaranteed at -20 °C, good weldability and high yield strength, S355J2 is a reliable structural steel for structures in outdoor environments, cold climates and under dynamic loads. For the right choice, delivery condition, thickness group and certificate values should be evaluated together. Get a quote for your S355 grade steel requirements: +90 (212) 485 98 98 or visit our contact page.