Description
Full-Range Square & Rectangular Tubes — S235JR through S355J2H in EN10210/EN10219, 15×15 mm to 1000×1000 mm, wall thickness up to 50 mm, cut to your drawing.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355JR / S355J2 Square Steel Tube |
| Product Type | Square and Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | S235JR, S275JR, S355JR, S355J2H, S355J0, ASTM A53 GR.B, Q460, A36, SS400 |
| Standard | EN10210, EN10219, ASTM A53, ASTM A500 |
| Section Shape | Square / Rectangular / Round |
| Size Range (Square) | 15×15 mm – 1000×1000 mm |
| Size Range (Rectangular) | 20×30 mm – 600×800 mm |
| Wall Thickness | 0.5 mm – 50 mm |
| Length | 5.8 m – 14 m (custom cut-to-length available) |
| Technique | ERW (Electric Resistance Welded) / Hot Rolled |
| Surface Treatment | Bare / Oiled / Painted / Galvanized / 3PE Coating / Varnish |
| Ends | Plain / Cut / Threaded / Beveled / Flanged |
| Tolerance | ±1% |
| Application | Urban & civil construction, machine structure, scaffolding, greenhouse, furniture, low-pressure fluid transport, agricultural equipment, building material frames |
| MOQ | 1 Ton |
| Origin | China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Steel Fabricators | Structural frames for warehouses, machine bases, equipment support columns |
| Construction Companies | Scaffolding systems, building material frames, civil infrastructure bracing |
| Agricultural & Greenhouse Builders | Greenhouse structural tubing, equipment shelters, crop support frames |
| Machine Builders | Conveyor structures, crane booms, hydraulic support frames |
| Furniture & Interior | Display racks, mezzanine structures, industrial shelving frames |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A 1 mm deviation on a 10 mm wall square tube can shift load capacity enough to fail structural sign-off.
When sourcing a S355JR S355J2 square steel tube supplier, fabricators frequently receive material that passes visual inspection but fails dimensional checks at the fabrication stage. Hidden negative tolerance practices mean the actual wall thickness falls below the declared value, reducing load-bearing capacity and causing weld joint misalignment on thick-wall sections. For projects governed by EN 1993 or equivalent national codes, inspectors will reject tubes that do not match the declared cross-section properties — and the rework cost falls on the buyer, not the mill. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
How Large-Section Square Tubes Match Structural Frame Requirements
Projects requiring 400×400 mm to 1000×1000 mm square sections with wall thickness above 20 mm face a supply gap — most traders stock only up to 300×300 mm and push buyers toward full-coil orders. As a S355JR S355J2 square steel tube supplier with ERW and hot-rolled capability, we hold ready stock in large-section SHS and RHS, cut to length per your fabrication drawing. For a warehouse frame project in West Africa, the client needed 500×500×25 mm S355J2H tubes in 12 m lengths — we supplied 48 tonnes with custom beveled ends, eliminating on-site cutting delays.
Engineering Compliance and Grade Selection for Structural Applications
Structural square tubes in S355JR and S355J2 must comply with EN 10210 for hot-finished or EN 10219 for cold-formed hollow sections, depending on the manufacturing route. The J0 and J2 variants add Charpy impact testing at 0°C and −20°C respectively — critical for outdoor structures in cold climates or dynamic-load applications like crane runways. For projects entering the EU market, CE marking per EN 10210 is mandatory for customs clearance; for North American projects, ASTM A500 Grade B or C equivalence must be documented. Surface treatment selection depends on the service environment: galvanized coating for coastal or high-humidity sites, 3PE for buried or underground structural supports, and bare oiled finish for indoor fabrication where painting follows on-site. [NEED_CITE: steel grade equivalence between EN S355 and ASTM A500 standards]
Steel Grade, Welding Process, and Surface Treatment Decoded
The S-series grades (S235JR, S275JR, S355JR, S355J2H) follow the European EN standard system where the number indicates minimum yield strength in MPa for thickness ≤16 mm. Q460 belongs to the Chinese GB system with higher yield strength, suitable for heavy-duty structural applications. ASTM A53 GR.B and A36 represent the American system — when a project drawing specifies ASTM A36 but the mill rolls S235JR, the equivalence must be verified against chemical composition and mechanical properties, not just the grade name. ERW welding produces a longitudinal seam suitable for structural applications up to moderate wall thickness; hot-rolled process handles heavy-wall sections above 20 mm where seam integrity under load becomes critical. Galvanized coating provides sacrificial zinc protection for 20–50 years depending on environment class, while 3PE coating combines epoxy primer with polyethylene outer layer for mechanical damage resistance during handling and burial.
Hidden Costs of Wrong Grade or Missing Certification
Ordering S355JR when the structural engineer specified S355J2 means the impact toughness at sub-zero temperatures is unverified — the tube may pass static load but crack under dynamic stress in cold weather. Missing mill test certificates trigger customs holds in the EU and Middle East, where import authorities require EN 10210 compliance documentation before release. Negative tolerance abuse means you pay for 10 mm wall but receive 9.2 mm — the weight-based pricing looks cheaper, but the structural calculation was based on declared properties, and the inspector will reject the batch. [NEED_CITE: structural steel hollow section certification requirements for EU customs]
Why Fabricators and EPCs Source from XJY Plate
We operate as a dedicated square and rectangular tube supplier with ready stock across 2800+ specifications in S235JR through S355J2H, eliminating the 8–12 week mill lead time for non-standard sizes. Every shipment carries an original mill test certificate with heat number traceability — chemical composition, yield strength, tensile strength, and elongation verified per EN 10210 or EN 10219. Our ISO 9001:2015 certified facility provides custom cut-to-length, beveling, threading, and flange welding per your fabrication drawing, with dimensional inspection reports attached to each bundle. For heavy-wall or large-section tubes, we design container loading plans with weight distribution calculations — avoiding port overweight penalties and on-site damage from improper stowage. Third-party inspection by SGS or BV is available before shipment for projects requiring independent verification.
Documentation & Compliance
- Mill test certificate documenting S355JR / S355J2 chemical composition, yield strength, and tensile properties per EN10210 or EN10219
- CE certificate confirming EN10210 / EN10219 compliance for EU market customs clearance
- ISO 9001:2015 quality management system certificate covering production and inspection processes
- SGS or BV third-party inspection report available upon request for project-specific verification
- Full material traceability by heat number linking each tube to its mill test certificate
- Export customs documents including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Heavy-wall S355J2 square tubes bundled with high-tensile steel strips and edge protectors to prevent corner damage during ocean transit
- Galvanized SHS/RHS packed with waterproof interleaving to preserve zinc coating integrity in humid container environments
- Container loading plan provided for each shipment, optimizing weight distribution for 20ft and 40ft open-top containers with tubes up to 14 m length
- Custom cut-to-length service available for 5.8 m to 14 m standard lengths or per fabrication drawing, with length tolerance ±5 mm
- Each bundle marked with heat number, steel grade, size, and length for on-site identification and traceability
- FOB, CIF, and DDP shipping terms available with professional flatbed and break-bulk logistics for project cargo exceeding container capacity
Start Your Procurement with Verified Specifications
Submit your drawing or specification list including steel grade, section size, wall thickness, length, quantity, and destination port — we respond within 12 hours with pricing, mill test certificate preview, and container loading plan. For non-standard sizes or custom end treatment, our engineering team provides cut-to-size proposals with dimensional reports.
Request Quotation and Mill Test Certificate
Send your specification to admin@xjyplate.com or contact via WhatsApp at +86 188 5315 7756 for pricing, MTC review, and delivery schedule.
Frequently Asked Questions
Q: What is the difference between S355JR and S355J2 for structural applications?
A: S355JR requires impact testing at room temperature (20°C), while S355J2 requires Charpy impact testing at −20°C. For outdoor structures in cold climates or dynamic-load applications, S355J2 provides verified low-temperature toughness. Both grades share the same minimum yield strength of 355 MPa for thickness ≤16 mm per EN 10210.
Q: Can I order small quantities of large-section square tubes without full-coil minimum?
A: Yes. We hold ready stock in large-section SHS and RHS up to 1000×1000 mm with 50 mm wall thickness, and our MOQ is 1 Ton. You can order cut-to-length pieces per your fabrication drawing without committing to full-coil or full-bundle quantities.
Q: How do you verify steel grade equivalence between EN, ASTM, and GB standards?
A: We compare chemical composition and mechanical properties from the mill test certificate against the target standard requirements. For example, S355JR equivalence to ASTM A572 Grade 50 requires matching carbon, manganese, and yield strength values — not just the grade name. We provide cross-reference documentation with each shipment.
Q: What surface treatment is recommended for outdoor structural applications in coastal environments?
A: Hot-dip galvanized coating provides sacrificial zinc protection suitable for coastal environments with C4–C5 corrosion classification per ISO 12944. For buried structural supports or underground applications, 3PE coating combines epoxy primer with polyethylene outer layer for mechanical damage resistance and long-term corrosion protection.
Q: How do you handle shipping heavy-wall square tubes to avoid damage and overweight penalties?
A: We design container loading plans with weight distribution calculations for each shipment. Heavy-wall tubes are loaded with proper dunnage and edge protectors to prevent corner deformation. For shipments exceeding container weight limits, we use open-top containers or break-bulk shipping with flatbed transport to port.
