Description
Factory-direct ERW square tubes — ASTM A500 GR.A/B and EN S235/S355 grades produced in-house with full CE and ISO documentation for EU and global customs clearance.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Welded Square Steel Tube |
| Product Type | Welded Square Steel Tube (ERW) |
| Steel Grade | Q195, Q215, Q235, Q345, GR.A, GR.B, S235, S355 |
| Standard | ASTM A500, EN 10219, JIS G3466, ISO 9001 |
| Section Shape | Square |
| Size Range | 10×10 – 600×600 mm |
| Wall Thickness | 0.8 – 30 mm |
| Length | 5.7 m / 6 m |
| Technique | Welded ERW |
| Surface Treatment | Pre-galvanized / Hot-dipped galvanized / Bare / Oiled |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Structure Pipe / Construction frames / Machinery / Fluid transport / Scaffolding |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Steel Structure Construction | Building frames, column supports, truss systems for warehouses and industrial plants |
| Architectural Facades | Curtain wall framing, decorative square pipe grids, exposed structural elements |
| Machinery Manufacturing | Equipment bases, conveyor supports, hydraulic frame structures |
| Infrastructure & Scaffolding | Scaffolding uprights, bridge formwork supports, temporary access structures |
| Fluid Transport | Low-pressure water lines, drainage channels, irrigation pipelines |
Where Wall-Thickness Tolerance Decides Structural Acceptance
A ±1% tolerance on 600×600 mm square tubes means the difference between passing inspector measurement and failing the entire batch at site.
Project engineers specifying ASTM A500 ERW square steel tube for load-bearing frames expect dimensional consistency across hundreds of pieces. When wall thickness drifts beyond tolerance — especially on thin-wall sections below 3 mm — connection plates do not seat flush, bolt holes misalign, and welding prep becomes inconsistent. The cost is not the steel itself but the rework hours and delayed handover that follow. Sourcing from mills without in-house dimensional testing labs means buyers discover these gaps only after containers arrive at destination ports [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements].
Matching Square Tube Specs to Structural Frame Requirements
Load-bearing frames for steel structure buildings require square tubes that maintain geometric integrity under compression and lateral loads. The 10×10 to 600×600 mm range covers everything from lightweight machinery bases to heavy column sections, while wall thickness from 0.8 to 30 mm allows engineers to select based on calculated stress rather than catalog availability. For ASTM A500 ERW square steel tube orders destined for EU projects, S235 and S355 grades meet EN 10219 requirements directly, eliminating the need for dual-certification paperwork at customs.
Engineering Compliance and Surface Protection Selection
Structural frames exposed to outdoor or humid environments require surface treatment decisions before fabrication begins. Pre-galvanized ASTM A500 ERW square steel tube provides zinc protection suitable for indoor mechanical supports and covered scaffolding, while hot-dipped galvanizing extends service life for outdoor infrastructure applications where corrosion resistance matters more than surface appearance. Bare or oiled finishes remain appropriate for tubes that will receive field-applied coatings or fireproofing after installation. CE certification under EN 10210 and EN 10219 ensures compliance with European construction product regulations, while ASTM A500 documentation satisfies North American specifiers [NEED_CITE: CE marking requirements for structural hollow sections under EN 10210].
Steel Grade Selection and ERW Welding Process
The Q-series (Q195–Q345) follows Chinese GB standards with yield strength increasing by grade number, while GR.A and GR.B represent the ASTM A500 equivalent system used across North American and international projects. S235 and S355 belong to the EN standard family, where S355 offers higher yield strength for heavy structural applications such as multi-story building columns and crane support frames. ERW welding produces a longitudinal seam suitable for square and rectangular hollow sections, offering cost advantages over seamless pipe for non-pressure structural applications while maintaining consistent wall thickness around the entire cross-section. The ±1% tolerance specification ensures that 6-meter lengths arrive with predictable weight and section modulus for engineering calculations.
Hidden Costs of Incorrect Grade or Missing Certification
Ordering Q235 when the project specification calls for S355 means lower yield strength than the structural engineer calculated for — the tubes may pass visual inspection but fail load testing during commissioning. Missing CE marks on EN 10219 tubes destined for EU construction sites trigger customs holds and potential rejection at the port, regardless of physical quality. Negative tolerance abuse — where actual wall thickness falls below the stated minimum — reduces load capacity and voids structural warranties, creating liability exposure for contractors who cannot prove material compliance after installation [NEED_CITE: steel grade equivalence between ASTM A500 and EN 10219 standards].
Why Project Buyers Source ASTM A500 ERW Square Steel Tube Here
Direct factory production eliminates trading company markups and provides traceability from billet to finished tube through heat number documentation. The in-house physical and chemical laboratory issues mill test certificates covering chemical composition and mechanical properties for every production batch, not just representative samples. Coverage of 2,800+ specifications across square, rectangular, and round profiles allows consolidated procurement for mixed-specification projects rather than splitting orders across multiple suppliers. Patented sharp-corner rectangular tube technology fills the gap where standard ERW tubes with rounded corners fail architectural facade requirements. Full international certification portfolio — ISO 9001:2015, Lloyd’s CE under EN 10210/10219, Singapore FPC, and SGS/BV verification — supports customs clearance across 50+ export destinations. Professional container loading with engineered bracing prevents the bending and surface damage that plague improperly stuffed tubes during ocean transit.
Documentation & Compliance
- Mill test certificate documenting S355 chemical composition and yield strength per EN 10219, issued from in-house laboratory with heat number traceability
- CE certificate covering EN 10210 and EN 10219 standards for structural hollow sections, required for EU construction product regulation compliance
- ISO 9001:2015 quality management certificate demonstrating systematic production control and inspection procedures
- SGS or BV third-party inspection report available upon request for projects requiring independent verification before shipment
- Material traceability by heat number linking each ASTM A500 ERW square steel tube to its original coil test results
- Complete customs documentation including packing list, bill of lading, and certificate of origin for destination port clearance
Packaging, Loading & Delivery
- 6-meter ASTM A500 ERW square steel tube bundled with steel strips and edge protectors to prevent corner damage during handling and transit
- Hot-dipped galvanized tubes packed with separation layers to preserve zinc coating integrity and avoid surface scratching
- Container loading optimized for 10×10 to 200×200 mm square tubes in 20GP and 40HQ, with engineered wooden cradles preventing shift during ocean freight
- Custom cutting to project-specific lengths available for orders requiring non-standard dimensions within the 5.7 m to 6 m range
- Heat number and steel grade marking on each tube end for site identification and inspection traceability
- FOB, CIF, and DDP shipping terms available with professional export documentation and tracking until destination arrival
Requesting Quotation and Technical Documentation
Submit your ASTM A500 ERW square steel tube requirements including section size, wall thickness, steel grade, surface treatment preference, quantity, and destination port to receive detailed pricing with mill test certificate samples. Non-standard dimensions and custom length requests receive technical feasibility confirmation within typical response windows. Certification requirements for specific destination markets — CE for EU, ASTM for North America, or local standards for Southeast Asia and Middle East — are confirmed before production begins to prevent customs complications.
Frequently Asked Questions
Q: Can you supply ASTM A500 GR.B square tubes with CE certification for EU projects?
A: Yes, our ASTM A500 ERW square steel tube production carries both ASTM and EN certifications. We provide CE marking under EN 10210 and EN 10219 for structural hollow sections, with mill test certificates documenting compliance to both standard systems for projects requiring dual documentation.
Q: What is the minimum order quantity for custom non-standard square tube sizes?
A: The MOQ is 1 Ton for standard specifications. Custom non-standard sizes outside the 10×10 to 600×600 mm range are available based on production feasibility — we cover 2,800+ specifications and can confirm dimensional availability upon receiving your specific requirements.
Q: Do you provide third-party inspection before shipment?
A: Yes, SGS and BV third-party inspection services are available upon request. We coordinate inspection scheduling with your designated surveyor and provide full access to production batches, dimensional testing, and mill test certificate review before container sealing.
Q: How do you ensure square tubes arrive without bending or surface damage?
A: We use engineered container loading with wooden cradles and anti-shift bracing specifically designed for square and rectangular hollow sections. Each loading plan accounts for tube dimensions, wall thickness, and weight distribution to prevent movement during ocean transit — a critical factor for 6-meter lengths in thin-wall specifications.
Q: Can you supply sharp-corner rectangular tubes for architectural facade applications?
A: Yes, we hold 41 patents including China’s original sharp-corner rectangular tube technology. These patented tubes provide true right-angle corners for glass curtain wall framing and architectural facades where standard ERW tubes with rounded corners fail aesthetic and structural connection requirements.
Get Your ASTM A500 ERW Square Steel Tube Quote with Mill Test Certificate
Send your specifications — section size, wall thickness, steel grade, surface treatment, quantity, and destination — to receive pricing, certification confirmation, and typical production lead times.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
