Description
Factory-Direct ERW Corten Square Steel Tube 80x40mm Supplier — Every 80×40×2mm tube rolls from our own mill with full chemical traceability, cutting out trading-company markups on structural frame orders.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355JR ERW Square Steel Tube |
| Product Type | Welded Square Steel Tube (ERW) |
| Steel Grade | S235JR, Q235B, A36, S355, SS400, Q345B |
| Standard | ASTM A500, EN 10219, EN 10210, JIS G3466, GB/T 6728 |
| Section Shape | Square |
| Side Length | 80×40 mm |
| Wall Thickness | 2 mm |
| Length | Customized |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Cold Rolled / Oiled or Non-oiled |
| Tolerance | ±1% |
| Ends | Plain |
| Invoicing | By Theoretical Weight |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Application | Steel structures, Construction frames, Machinery manufacturing, Furniture frames, Infrastructure construction, Vehicle manufacturing, Scaffolding |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Steel Fabricators | Structural frames for warehouses, machinery bases, conveyor supports |
| Construction Companies | Building frames, scaffolding uprights, infrastructure bracing |
| Furniture Manufacturers | Rack frames, handrail posts, display shelving structures |
| Vehicle Manufacturing | Trailer chassis sub-frames, equipment mounting brackets |
What Negative Tolerance Really Costs on an 80×40 Structural Frame
A 2mm wall that measures 1.7mm at the weld seam fails load calculations before the first bolt goes in.
On a recent Riyadh landscape project, a batch of rectangular hollow sections arrived with wall thickness deviations so severe that the site supervisor pulled a caliper and rejected the entire lot. The supplier had invoiced by theoretical weight while delivering well under spec — the buyer paid for 2mm steel and received something closer to 1.6mm at critical points. When you are framing a structure that must pass third-party inspection, every tenth of a millimeter on a 2mm wall changes the moment of inertia and the buckling resistance. An ERW Corten Square Steel Tube 80x40mm supplier who controls tolerance at ±1% gives you predictable structural behavior, not a gamble on which tube the inspector picks to measure. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed hollow sections]
Matching 80×40 Sections to Structural Frame Geometry
The 80×40 rectangular profile sits in a practical sweet spot for secondary structural members — stiff enough to resist lateral deflection in scaffolding uprights and conveyor supports, yet light enough for manual handling on site. When you specify an ERW Corten Square Steel Tube 80x40mm in S355JR or S235JR, the cold-rolled surface gives a clean finish for exposed architectural frames, while the oiled condition protects against transit corrosion without adding coating thickness that interferes with welding prep. Our mill holds running stock in both S235JR and S355JR across this section, so fabricators ordering mixed grades for a single project get one shipment instead of three.
Engineering Compliance and Certification Pathways
Structural hollow sections for load-bearing frames in European markets must conform to EN 10219 for cold-formed welded profiles, which governs dimensional tolerances, weld integrity, and chemical composition limits. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections technical delivery conditions] For North American projects, ASTM A500 Grade B or C applies, with different tolerance tables and tensile requirements. Our ERW Corten Square Steel Tube 80x40mm ships with CE marking under EN 10219, ISO 9001:2015 quality certification, and original mill test certificates that trace every heat number back to the slab chemistry. Customs authorities in the EU and Middle East increasingly require verifiable MTC documentation — a certificate without a readable heat number is a shipment held at the port.
Steel Grade Selection and ERW Process Fundamentals
S235JR and S355JR represent the two most specified non-alloy structural grades under EN 10025, with S355JR offering roughly 50% higher minimum yield strength — the difference between a member that works in a mezzanine floor and one that needs upsizing for the same span. Q235B and Q345B serve the same roles in the Chinese GB system, while A36 and SS400 cover equivalent ground in ASTM and JIS respectively. The ERW process forms the tube from cold-rolled coil through progressive roll forming and resistance-welds the seam without filler metal, producing a clean internal profile suitable for concrete filling or hidden structural connections. Cold-rolled surface treatment on these 80×40 sections delivers tighter dimensional accuracy than hot-rolled alternatives, which matters when you are punching connection holes at 40mm centers. Wall thickness at 2mm on this section keeps the weight manageable for manual installation while the ±1% tolerance ensures that nested frame assemblies fit without forced alignment. [NEED_CITE: steel grade equivalence between EN 10025, ASTM A500, and GB/T 6728 standards]
Hidden Costs of Unverified Tube Procurement
Ordering structural hollow sections without verified mill test certificates means you cannot prove grade compliance when the inspector asks — and “trust me, it is S355” does not pass a site audit. Tubes that exceed negative tolerance limits look identical to spec-compliant material from the outside, but they carry reduced section modulus and fail under design loads. A shipment held at customs for missing CE documentation or unreadable heat-number markings incurs demurrage charges that dwarf any per-ton price saving. When you source an ERW Corten Square Steel Tube 80x40mm from a supplier who cannot produce traceable MTCs, you are absorbing the risk of re-rolling, re-shipping, and project delay. [NEED_CITE: structural steel procurement traceability requirements for CE marking]
Why Fabricators and EPCs Source This Section From Us
We roll our own ERW tubes in-house, which means the price you see reflects mill cost plus processing — no trading margin layered on top. Every bundle of 80×40×2mm tube carries a heat-number sticker tied to a mill test certificate that documents chemical composition and mechanical test results, not a re-inspector’s guess. Our inventory covers S235JR, Q235B, A36, S355, SS400, and Q345B in this section, so a fabricator ordering mixed grades for a single project gets consolidated loading. Custom cutting to site-specific lengths reduces on-site waste and welding time. We hold CE certification under EN 10219 and EN 10210, ISO 9001:2015 registration, and can arrange SGS or BV third-party inspection before shipment. For heavy flat-product logistics, our loading team uses flatbed and open-top container configurations engineered for steel tube — no crushed edges from improper stacking.
Documentation & Compliance
- Mill test certificate documenting S235JR or S355JR chemical composition and mechanical properties per EN 10219, with readable heat number traceability
- CE certificate covering EN 10219 cold-formed welded structural hollow sections for EU market customs clearance
- ISO 9001:2015 quality management system certificate covering the full production and inspection process
- SGS or BV third-party inspection report available upon request, verifying dimensional tolerance and surface condition before loading
- Material traceability sheet linking each bundle heat number to slab chemistry and rolling records
- Full customs documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Cold-rolled oiled tubes bundled with steel straps and edge protectors to preserve surface finish during ocean transit
- 80×40mm sections nested and strapped in rectangular bundles optimized for 20ft and 40ft open-top container loading without exceeding weight limits
- Custom cut-to-length service available, with each piece marked by heat number and steel grade for site identification
- Plain-end tubes packed with end caps or protective wrapping to prevent moisture ingress and edge damage
- FOB, CIF, and DDP shipping terms available, with professional flatbed and break-bulk logistics for project cargo
- Every bundle tagged with steel grade, wall thickness, and heat number for receiving inspection verification
Getting a Firm Quote on 80×40×2mm ERW Tube
Send us your required steel grade, total tonnage or piece count, cut lengths if needed, and destination port — we return a detailed quotation within 12 hours, including material cost, any processing fees, and shipping terms. If your project requires mixed grades or non-standard lengths from this section, we confirm availability and lead time before you commit. All quotes include the mill test certificate and CE documentation at no extra charge, so you can verify compliance before the deposit goes out.
Frequently Asked Questions
Q: Can you supply the ERW Corten Square Steel Tube 80x40mm in both S235JR and S355JR from the same order?
A: Yes. We hold stock in S235JR, Q235B, A36, S355, SS400, and Q345B across this section, and can consolidate mixed-grade orders into a single shipment with separate heat-number traceability for each grade.
Q: How do you verify that the 2mm wall thickness meets the ±1% tolerance?
A: Every production batch undergoes dimensional inspection at our mill, and we provide a dimensional report alongside the mill test certificate. Third-party inspection by SGS or BV is available before loading if your project requires independent verification.
Q: Is the theoretical weight invoicing accurate for the 80×40×2mm section?
A: We invoice by theoretical weight calculated from the nominal dimensions and standard steel density, but our ±1% wall-thickness tolerance ensures the actual delivered weight stays within a narrow band of the theoretical figure — no hidden negative tolerance surprises.
Q: What surface treatment options are available for this cold-rolled ERW tube?
A: The standard supply condition is cold-rolled with oiled or non-oiled finish. Galvanized coating is available on request for applications requiring additional corrosion protection beyond the oiled transit condition.
Q: Can you cut the tubes to specific lengths for our fabrication shop?
A: Yes. Custom cutting is part of our standard processing service, and we can supply the 80×40mm section in project-specific lengths to reduce on-site cutting waste. Just specify your required lengths when you inquire.
Request Your ERW Corten Square Steel Tube 80x40mm Quotation
Submit your steel grade, quantity, cut lengths, and destination port to receive a detailed quotation with mill test certificate and CE documentation within 12 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjyplate.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjyplate.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
