Description
ASTM A500 Welded Square Steel Tube 19-800mm SHS Manufacturer
Factory-Direct SHS Production — XJY Structure operates its own steel mill with 3 production lines and 2,800+ raw material specifications, delivering ASTM A500 welded square steel tubes from slab to finished section under one quality system.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Welded Square Steel Tube |
| Product Type | Welded Square Steel Tube / Square Hollow Structural Section (SHS) |
| Steel Grade | Gr.B, S235, S275, S355, STK400, Q235B, Q345B |
| Standard | ASTM A500, ASTM A53, GB/T 3091 |
| Section Shape | Square |
| Size Range | 19mm×19mm – 800mm×800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Construction structures, Building frames, Curtain walls, Support structures, Industrial structures, Fertilizer equipment |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Steel frame structures for warehouses, logistics centers, and multi-story buildings |
| Industrial Infrastructure | Platform support structures, equipment frames, and fertilizer plant frameworks |
| Architectural Engineering | Curtain wall support tubes, façade framing, and decorative structural columns |
| EPC & General Contracting | Column and beam assemblies for Middle East, Southeast Asia, and African construction projects |
What Negative Tolerance Drift Costs on a Square Tube Order
A wall thickness that slips beyond ±1% turns a compliant shipment into a rejected container at the destination port.
Overseas buyers sourcing square hollow sections from disconnected traders face a recurring nightmare: the mill test certificate looks clean on paper, but when a caliper touches the tube at the unloading site, the wall thickness tells a different story. I have seen entire container loads of welded square tubes滞留 at West African ports because the wall negative tolerance exceeded acceptable limits — the buyer had no leverage since the trader sourced from a third-party mill with no direct quality oversight. Material traceability gaps between the steel supplier and the tube fabricator create exactly this kind of exposure, where nobody in the supply chain takes accountability for dimensional accuracy. [NEED_CITE: structural hollow section dimensional tolerance requirements per EN 10219]
How 19×19 to 800×800mm SHS Matches Structural Frame Requirements
The size range of ASTM A500 welded square steel tube from 19mm×19mm to 800mm×800mm with wall thickness from 1 to 30 mm covers virtually every load-bearing requirement in commercial and industrial construction. Small-section tubes serve as curtain wall mullions and light-duty bracing members, while large-section SHS with heavier wall thickness function as primary columns and transfer beams in warehouse and logistics center frames. The ERW welding process ensures consistent seam quality across the full size spectrum, which matters when a single project may call for both 50×50×3 bracing tubes and 400×400×16 main columns. Our vertically integrated production — from raw steel slab through to finished and inspected SHS — means every section carries the same heat number traceability regardless of dimension.
Meeting Engineering Codes and Customs Clearance Across Markets
Structural hollow sections used in load-bearing frames must comply with the engineering standards specified by the project’s design team, and the documentation must satisfy customs authorities at the destination country. For European projects, ASTM A500 welded square steel tube orders often require cross-referencing to EN 10219 cold-formed hollow sections, with CE marking and EN 10204 3.1 or 3.2 mill test certificates. North American projects specify ASTM A500 Gr.B directly, and the MTC must confirm chemical composition and mechanical properties against that standard. Asian infrastructure projects frequently accept Q235B or Q345B equivalents under GB/T 3091. Missing or inconsistent certification between the tube and the declared standard is one of the most common reasons for customs delays on structural steel shipments. [NEED_CITE: steel grade equivalence between ASTM A500 and EN 10219 standards]
Steel Grade Selection and ERW Welding Fundamentals
The available steel grades — Gr.B, S235, S275, S355, STK400, Q235B, Q345B — represent three major standard systems that converge on the same product family. S235, S275, and S355 follow the European EN system with incrementally higher yield strength, making S355 the preferred choice for heavy-load columns and moment-resisting frames. The ASTM A500 Gr.B specification dominates North American construction, while Q235B and Q345B serve the Chinese GB/T system commonly specified on Belt & Road infrastructure projects. The ERW (Electric Resistance Welded) process forms the square section by cold-forming a steel strip and welding the seam through electrical resistance heating — this produces a clean, consistent weld line suitable for structural applications without the cost premium of seamless manufacturing. Surface treatment selection depends on the corrosion environment: hot-dip galvanizing provides long-term protection for outdoor and coastal installations, black painting suits indoor or temporarily protected conditions, and bare tubes are specified when the project contractor handles coating on site. Wall thickness tolerance of ±1% ensures that theoretical weight calculations align with actual delivered weight, preventing billing disputes and structural miscalculations.
The Hidden Cost of Sourcing SHS Without Mill-Level Accountability
When buyers purchase ASTM A500 welded square steel tube through intermediaries who source from unnamed subcontractors, the risks compound silently. Material certificates may be transferred between parties without verified heat-to-piece traceability, meaning the MTC on file does not necessarily correspond to the tubes in the container. Negative tolerance drift — where wall thickness falls below the specified minimum — passes undetected until on-site inspection, triggering rework, structural recalculation, or outright rejection. Certification gaps become critical at customs: a shipment declared under ASTM A500 but lacking proper MTC documentation faces holds, re-inspection fees, and potential return. For EPC firms managing project timelines, these delays cascade into schedule overruns that dwarf the original material cost savings from choosing an unverified supplier. [NEED_CITE: structural steel procurement quality assurance requirements for international EPC projects]
Why Project Teams Source ASTM A500 SHS Directly from Our Mill
XJY Structure eliminates the traceability gap by producing the raw steel and fabricating the finished tube within a single integrated facility. Every ASTM A500 welded square steel tube we ship carries a mill test certificate generated from our own in-house laboratory, with full heat number traceability from slab to finished section. Our raw material inventory covers 2,800+ specifications, which means projects requiring mixed steel grades — say S355 for main columns and S235 for secondary bracing — can be fulfilled from a single purchase order without coordinating multiple suppliers. Welding procedures are certified under WPS/PQR with qualified welders holding AWS and EN certifications, and every batch undergoes dimensional inspection and, when specified, non-destructive testing before release. For European market shipments, we provide CE marking and EN 10210/EN 10219 compliance documentation; for projects requiring third-party verification, we coordinate SGS, BV, or TÜV inspections at our facility prior to loading. Custom non-standard sizes and project-specific cut lengths are handled directly by our engineering team, with shop drawing review and material optimization support included in the quotation process.
Documentation & Compliance
- Mill test certificate documenting ASTM A500 Gr.B chemical composition and mechanical properties per heat number, issued in EN 10204 3.1 format
- CE certificate confirming EN 10219 cold-formed hollow section compliance for S235/S275/S355 grades shipped to European Union markets
- ISO 9001 quality management system certificate covering the full production process from raw material incoming inspection to final dimensional and coating checks
- SGS or BV third-party inspection report available upon request, covering visual examination, dimensional verification, and coating thickness measurement for galvanized ASTM A500 welded square steel tube
- Full material traceability linking each tube to its heat number, with test records retained for project audit requirements
- Complete customs documentation package including packing list, bill of lading, and certificate of origin formatted for destination country import requirements
Packaging, Loading & Delivery
- ASTM A500 welded square steel tubes bundled with steel strips in seaworthy packaging, with bundle weight optimized for 20ft and 40ft container loading based on section size and wall thickness
- Galvanized SHS packed with edge protectors and moisture-resistant separators to preserve the zinc coating surface during ocean transit to coastal construction sites
- Black painted and varnished tubes wrapped in waterproof paper with steel frame support to prevent surface damage during handling and transport
- Random length and cut-to-length orders of 5.8m, 6m, 11.8m, and 12m loaded with wooden chocks and steel wire lashing to prevent shifting inside the container
- Each bundle marked with heat number, steel grade (Gr.B / S355 / Q345B), section dimensions, and production batch for on-site identification and traceability verification
- Delivery terms available as FOB, CIF, or DDP with professional oversized cargo loading planning for large-section SHS up to 800×800mm
Ready to Start Your SHS Procurement?
Share your project drawings, required steel grades, section dimensions, wall thickness, quantity, and destination port — our engineering team responds within 24 hours with a detailed quotation including material cost, fabrication, surface treatment, packing, and shipping, along with the mill test certificate format and production schedule. For projects requiring non-standard sizes or mixed-grade orders, we provide shop drawing review and material optimization recommendations before contract signing.
Request Your ASTM A500 SHS Quotation Today
Submit your specifications and receive a full quotation with mill test certificate documentation within 24 hours.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: What is the difference between ASTM A500 Gr.B, S355, and Q345B for square hollow sections?
A: These three steel grades belong to different standard systems but serve similar structural functions. ASTM A500 Gr.B is the North American standard specification for cold-formed welded and seamless carbon steel structural tubing. S355 follows the European EN system and offers higher yield strength than S235 and S275, making it suitable for heavier structural frames. Q345B is the Chinese GB/T standard equivalent commonly specified on infrastructure projects across Asia and Africa. We can supply all three grades from our integrated mill and provide cross-reference documentation when projects require grade substitution approval.
Q: Can you provide third-party inspection before shipment for ASTM A500 welded square steel tube?
A: Yes. We coordinate third-party inspections through SGS, BV, or TÜV at our facility before loading. The inspection scope typically covers visual examination, dimensional verification including wall thickness and section geometry, surface treatment coating thickness measurement for galvanized tubes, and review of mill test certificates. The inspection report is issued directly to the buyer and forms part of the shipping documentation package.
Q: What is the minimum order quantity for custom non-standard sizes?
A: Our standard MOQ is 5 tons for regular stock sizes within the 19mm×19mm to 800mm×800mm range. For custom non-standard dimensions or project-specific cut lengths outside our standard offering, the MOQ depends on the section size and total tonnage required. Since we operate our own steel mill with 2,800+ raw material specifications, we can accommodate smaller custom runs compared to standalone tube mills that require minimum rolling campaign quantities.
Q: How do you handle wall thickness tolerance and billing weight for welded square tubes?
A: Our ASTM A500 welded square steel tube is produced to ±1% dimensional tolerance. Billing can be arranged on theoretical weight or actual weight basis depending on the buyer’s preference and the destination market convention. We clearly state the tolerance policy and billing method in the quotation to prevent disputes at delivery. For projects where wall thickness is critical for structural calculations, we recommend specifying actual weight billing and requesting pre-shipment third-party dimensional inspection.
Q: What surface treatment options are available and how do I choose between them?
A: We offer four surface treatment options: black painting for indoor or short-term outdoor use, hot-dip galvanizing for long-term corrosion protection in outdoor and coastal environments, varnish coating for moderate protection requirements, and bare (uncoated) for projects where the contractor applies the final coating system on site. The choice depends on the project’s corrosion environment, the expected service life before maintenance, and whether the tubes will be further processed or welded after delivery. Our engineering team can advise on the most cost-effective option based on your specific application conditions.
