S355JR(E355B) Square Steel Pipe
Product description:

The S355JR (E355B) square steel pipe is a high-strength structural tube made from low-alloy, high-tensile steel. It is widely used in construction, machinery, transportation, and mechanical structures where durability, load-bearing capacity, and reliability are essential.

With its excellent strength-to-weight ratio, superior weldability, and consistent dimensional accuracy, the S355JR (E355B) square steel pipe is ideal for both heavy-duty and precision applications. Its square cross-section provides superior torsional resistance and stability compared to round tubes, making it a preferred choice for modern engineering and structural projects.

Square and rectangular sectioned steel pipes are collectively referred to as square and rectangular sectioned steel pipes, and they belong to a type of welded steel pipes. They are also known as "steel cold-formed sections".

Due to their unique cross-sectional shape and excellent mechanical properties, square and rectangular sectioned steel pipes are widely used in modern industries, construction and manufacturing, and have become an indispensable basic steel material.

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Material Overview

S355JR and E355B are European standard structural steels with similar mechanical properties:

S355JR (EN 10025-2): A non-alloy structural steel known for high yield strength and excellent impact resistance at low temperatures.

E355B (EN 10305-3 / EN 10210): A seamless and precision steel grade designed for high mechanical performance, excellent formability, and superior surface quality.

Both materials feature carbon-manganese compositions that provide a strong yet ductile structure, allowing easy forming, cutting, and welding.

Manufacturing Process

S355JR (E355B) square steel pipes are manufactured through advanced hot-finished or cold-formed processes, ensuring precision and consistency:

• Raw Material Preparation: High-quality billets are selected and heated to a controlled temperature.
• Forming: Pipes are shaped by hot rolling, ERW (Electric Resistance Welding), or seamless extrusion.
• Cold Finishing: Cold drawing or sizing ensures tighter tolerances and smooth surfaces.
• Heat Treatment: Normalizing or annealing improves strength and uniformity.
• Surface Treatment: Black coating, pickling, galvanizing, or painting for corrosion protection.
• Testing: Dimensional, mechanical, and non-destructive testing for quality assurance.

Key Features and Benefits

• High Structural Strength: Supports heavy loads and resists deformation under stress.
• Excellent Weldability: Suitable for all common welding methods (MIG, TIG, SMAW).
• Superior Dimensional Accuracy: Ideal for precise assembly and fabrication.
• Outstanding Corrosion Resistance: Available with protective coatings for long service life.
• Smooth Surface Finish: Improves appearance and reduces friction loss in machinery.
• Versatile Applications: Suitable for both indoor and outdoor structural systems.
• Good Impact Toughness: Performs well under dynamic loads and low temperatures.

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Applications:

Used Of Industries:

• Construction & Infrastructure: Columns, beams, frameworks, bridges, and platforms.
• Machinery & Equipment: Machine frames, conveyors, agricultural equipment, and cranes.
• Automotive & Transport: Vehicle chassis, trailers, and heavy truck components.
• Energy & Oil Equipment: hydraulic cylinders, pressure vessels, and structural supports.
• Furniture & Architecture: Modern steel furniture, decorative frames, and handrails.
• Shipbuilding & Marine Structures: Corrosion-protected components for offshore platforms.
• Its combination of performance, economy, and reliability makes it one of the most widely used square steel tube grades worldwide.

Surface Treatment Options

To enhance corrosion resistance and aesthetic appeal, several surface finishes are available:

• Hot-Dip Galvanized: Maximum corrosion protection for outdoor and marine use.
• Black or Oiled Surface: Prevents rust during storage and transport.
• Pickled and Passivated: Removes scale and enhances surface cleanliness.
• Powder Coating or Painting: Adds color and UV resistance for decorative applications.
• Polished Finish (for precision tubes): Smooth, clean, and visually appealing surface.

Company profile:

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Why us?

We focus on the research, development, production and sales of seamless steel pipes, Special-shaped steel pipes and hydraulic cylinders. We have a complete production chain and an advanced equipment system, including piercing machines, cold drawing machines, hot rolling machines, high-precision flaw detection and testing equipment. The company has passed multiple authoritative certifications such as ISO9001, API, SGS, CCS, DNV, ABS, CE, RoHS, etc., ensuring that each product complies with international standards. We are committed to providing customers with high-quality, customizable solutions to meet diverse application needs.

Relying on our own built processing base and modern workshops, combined with multiple branches and storage centers across the country, we have achieved sufficient inventory and efficient logistics coordination, significantly shortening the delivery cycle and ensuring the rapid delivery of orders.

We have established a complete service and support system. After the order is signed, the professional after-sales team can provide timely and safe on-site guidance and technical support to ensure that customers are at ease throughout the process from procurement to use.

FAQ:

1. Do you support customized design and production?

Sure. We have a professional engineering team that can conduct customized design and production with special sizes, control systems or OEM according to your requirements.

2. How fast can you deliver?

In stock sizes, it takes 3-5 days. For customized sizes, it takes 30-35 days.

3. What payment methods do you support?

We support TT payment. Generally, 30% to 50% of the payment is made in advance, and the remaining amount is paid before shipment.

4. Can you provide material certification (MTC)?

Yes, we will provide MTC to you after production is completed to ensure that the material quality meets the standards.

5. What is the minimum order quantity?

Generally, we accept trial orders. The minimum order quantity is 1-3 tons, which can be determined according to different products.