Description
Factory-Direct ERW Rectangular Hollow Sections — Q195 to Q345 grades rolled on our own ERW lines with ±1% tolerance, shipped with original mill test certificates and CE/EN compliance documents.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235/Q345 ERW Welded Rectangular Steel Hollow Section |
| Product Type | Welded Rectangular Steel Tube (Hollow Section) |
| Steel Grade | Q195, Q215, Q235, Q345 |
| Standard | ASTM A213, DIN EN 10217-1 |
| Section Shape | Rectangular (Square and Round also available) |
| Size Range | 20×20 mm, 50×25 mm, 60×40 mm, 80×40 mm, 50×50 mm |
| Wall Thickness | Per customer request |
| Length | Customer’s Request |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Hot Rolled / Slightly Oiled |
| Tolerance | ±1% |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Application | Fluid Pipe, Boiler Pipe, Drill Pipe, Gas Pipe, Oil Pipe, Chemical Fertilizer Pipe, Structure Pipe |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Structural frames, scaffolding systems, building column supports |
| Machinery & Equipment | Machine base frames, conveyor structures, equipment mounting brackets |
| Industrial Piping | Low-pressure fluid lines, gas distribution, chemical fertilizer transport pipelines |
| Energy & Utilities | Solar panel mounting structures, wind farm access platforms |
What Dimensional Tolerance Costs on a Structural Frame Order
A ±1% tolerance on a Q235 Q345 ERW welded rectangular steel hollow section supplier order is the difference between on-site bolt alignment and full-bay rework.
When rectangular hollow sections arrive with wall thickness drifting beyond tolerance, connection plates don’t sit flush and bolt holes misalign by millimeters that compound across a multi-bay frame. I’ve seen entire scaffold bays dismantled because the outer dimensions were off by fractions that looked negligible on a caliper but destroyed the geometry at scale. Fragmented sourcing makes this worse — buying tubes, plates, and sections from separate yards means nobody owns the cumulative tolerance stack. [NEED_CITE: EN 10219 cold-formed structural hollow section dimensional tolerance requirements]
Matching ERW Rectangular Sections to Structural Load Paths
The Q235 and Q345 grades in this Q235 Q345 ERW welded rectangular steel hollow section supplier range cover the yield strength band most structural engineers specify for building frames and machinery bases. Q235 handles general framing where moderate load capacity suffices, while Q345 steps up for heavier point loads and longer spans. The ERW seam runs along the flat face of the rectangle, keeping the corner radii tight and predictable — critical when these sections mate with gusset plates or bolted end connections. Our in-house cutting and punching services mean the sections arrive on site at exact lengths with pre-drilled connection holes, eliminating the field-cutting delays that eat into crane rental budgets.
Engineering Compliance and Certification Requirements
Structural hollow sections destined for European markets must conform to EN 10219 dimensional and material requirements, while North American projects typically reference ASTM A500. [NEED_CITE: steel grade equivalence mapping between GB Q-series and EN/ASTM standards] The Q235 Q345 ERW welded rectangular steel hollow section supplier documentation we provide includes CE marking under EN 10210/10219, ISO 9001:2015 quality certification, and original mill test certificates with heat-number traceability. For corrosive environments — coastal construction, chemical plants, outdoor scaffolding — the hot-rolled slightly oiled finish provides transit protection, with galvanized or painted options available as secondary processing. Custom lengths and non-standard section sizes are produced on our three active ERW lines with typical production lead times, and every batch passes three-stage in-house inspection before release.
Understanding ERW Welding and Grade Selection for Rectangular Hollow Sections
Electric Resistance Welding fuses the strip edges under high-frequency current without filler metal, producing a seam that matches the parent metal’s strength when properly controlled. This makes ERW rectangular hollow sections cost-effective for structural and low-pressure fluid applications where seamless pipe’s premium isn’t justified. The Q-series grading system (Q195 through Q345) denotes minimum yield strength in MPa — Q195 suits light framing and fencing, Q235 covers general structural work, and Q345 handles heavier beams and columns. Wall thickness tolerance directly affects theoretical weight calculations: a section running at the negative edge of tolerance weighs less per meter than the catalog figure suggests, which matters when procurement is priced by weight but structural design assumes nominal dimensions. [NEED_CITE: impact of wall thickness tolerance on structural hollow section weight and load capacity]
Hidden Costs of Incorrect Grade or Missing Certification
Specifying Q235 when the structural engineer calculated for Q345 doesn’t show up until load testing or — worse — until service deflection exceeds limits. Missing or incomplete mill test certificates trigger customs holds at destination ports, sometimes for weeks, while project cranes sit idle. [NEED_CITE: customs clearance failures due to incomplete steel mill test documentation] Sections that fail third-party SGS or BV inspection on arrival require either return shipping at the buyer’s cost or local re-melting scrap value — neither option recovers the project timeline. The Q235 Q345 ERW welded rectangular steel hollow section supplier you choose must provide heat-number traceability from slab to finished tube, not just a generic certificate detached from the actual shipment.
Why Source ERW Rectangular Hollow Sections From Xin Jiyuan
We run three ERW production lines simultaneously, giving us monthly capacity exceeding 20,000 tons and the flexibility to split a single order across multiple section sizes into one consolidated container. Our inventory covers 2,800+ specifications in ready stock, so standard Q235 and Q345 rectangular sections in common sizes ship within days rather than weeks. Every bundle carries original mill test certificates showing chemical composition and mechanical properties for that specific heat number — not recycled documents from a different batch. Third-party inspection through SGS or BV is arranged on request before container sealing. Our export team handles customs documentation, container loading optimization for mixed-size orders, and coordinates FOB/CIF/DDP shipping terms. Volume-based discount programs apply for recurring procurement, with pricing reviewed every six months for long-term partners.
Documentation & Compliance
- Mill test certificate documenting Q235 and Q345 chemical composition, yield strength, and tensile properties per heat number, conforming to ASTM A213 and DIN EN 10217-1
- CE certificate covering EN 10210 hot-finished and EN 10219 cold-formed structural hollow sections for European market compliance
- ISO 9001:2015 quality management system certificate covering production, inspection, and dispatch processes
- SGS or BV third-party inspection report available upon request, verifying dimensional tolerance, surface quality, and material grade before shipment
- Full material traceability by heat number from steelmaking slab through ERW forming to finished rectangular hollow section
- Export customs documents including packing list, bill of lading, and certificate of origin tailored to destination country requirements
Packaging, Loading & Delivery
- ERW welded rectangular tubes bundled with steel strips and edge protectors to prevent corner damage during handling and ocean transit, with hot-rolled slightly oiled surface preserved under waterproof wrapping
- Mixed-size container loading optimized for 20×20 mm through 80×40 mm rectangular sections, maximizing cubic utilization while maintaining weight distribution within port crane limits
- Custom-length cutting to customer specification before bundling, eliminating on-site cutting waste and reducing scrap disposal costs at the project location
- Heat number and steel grade (Q195/Q215/Q235/Q345) stenciled on each bundle tag, matching mill test certificate documentation for site inspection verification
- FOB, CIF, and DDP shipping terms available with professional export coordination for documentation, customs clearance, and port-to-site logistics across 50+ destination countries
Getting a Quote for Your Rectangular Hollow Section Project
Submit your section dimensions, steel grade preference, total tonnage, and destination port via email or WhatsApp to receive a competitive bulk quotation within 12 hours. The quote includes volume discount pricing, FOB/CIF terms, production lead time, and payment schedule. Request original mill test certificates and third-party inspection reports at the inquiry stage to confirm compliance with your project specifications before contract signing.
Frequently Asked Questions
Q: What are the steel grade equivalents between Q235/Q345 and international standards like EN or ASTM?
A: Q235 generally corresponds to S235 in EN standards and ASTM A283 Grade C in American specifications, while Q345 maps to S355 in EN and ASTM A572 Grade 50. Exact equivalence depends on chemical composition and mechanical property requirements for your specific application, and our technical team provides grade conversion guidance during the quotation stage.
Q: Can you arrange third-party inspection for bulk shipments of rectangular hollow sections?
A: Yes, SGS and BV third-party inspections are available on request for any order volume. The inspection covers dimensional verification, surface quality assessment, weld seam integrity, and material grade confirmation against the mill test certificate before container sealing.
Q: What is the minimum order quantity for non-standard rectangular section sizes?
A: The standard MOQ is 5 tons, which applies to both stock sizes and custom-produced non-standard dimensions. Non-standard sections typically require typical production lead times depending on specification complexity and current line scheduling.
Q: How do you handle container loading for orders with mixed rectangular and square section sizes?
A: Our export team creates optimized loading plans that nest different section sizes to maximize container cubic utilization while maintaining weight distribution within safe lifting limits. This consolidation reduces per-ton shipping costs compared to ordering each size in separate containers.
Q: What surface treatment options are available beyond the standard hot-rolled slightly oiled finish?
A: In addition to the standard hot-rolled slightly oiled surface, we offer hot-dip galvanizing for corrosion protection in outdoor or humid environments, and painted coatings in customer-specified colors and thicknesses. Galvanized and painted options affect both pricing and production scheduling, which we detail in the initial quotation.
Request Your Q235 Q345 ERW Rectangular Hollow Section Quotation Today
Send your specifications, steel grade, quantity, and destination port to receive factory-direct pricing with mill test certificates within 12 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
