Description
Factory-Direct ERW Square Tubes — Every ASTM A500 welded square steel tube ships with original mill test certificates and traceable heat numbers directly from our Jinan production lines.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Welded Square Steel Tube |
| Product Type | Welded Square Steel Tube (Square Hollow Section) |
| Steel Grade | Gr.B, S235, S275, S355, STK400 |
| 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 (Welded) |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Construction structures / Building frames / Curtain walls / Support tubes / Structural pipe |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Building frames, curtain wall support structures, column sections |
| Industrial Infrastructure | Scaffolding systems, conveyor support frames, equipment bases |
| Machinery Fabrication | Machine frames, hydraulic support tubes, structural brackets |
Where Tolerance Stacks Up on a Structural Frame Order
A ±1% tolerance on an 800×800mm SHS is the difference between a clean bolt-line fit and on-site rework.
When procurement teams source ASTM A500 welded square steel tube from fragmented suppliers, dimensional inconsistency across batches forces welders to shim connections or cut sections to compensate. Worse, missing or incomplete mill certificates trigger customs holds at destination ports — a problem that compounds when CE or EN 10219 documentation is required for European projects. [NEED_CITE: EN 10219 cold-formed welded hollow section dimensional tolerances]
Matching Load Paths and Connection Geometry
ERW welded square hollow sections in Gr.B and S355 grades provide flat bearing surfaces that align directly with gusset plates and base connections — eliminating the gapping issues common with rounded-corner alternatives. Our 19×19mm to 800×800mm range covers everything from light-gauge curtain wall purlins to heavy column sections, with wall thickness up to 30mm for primary structural members. Each ASTM A500 welded square steel tube rolls through three-stage inspection before leaving the Jinan warehouse.
Structural Compliance and Surface Protection
Design engineers specifying ASTM A500 Gr.B or EN S355 grades require documented chemical composition and yield strength for structural calculations. [NEED_CITE: steel grade equivalence between ASTM A500 and EN 10219 standards] For outdoor or corrosive environments, galvanized or painted surface treatments extend service life without additional field coating. Mill test certificates accompany every shipment, with SGS or BV third-party inspection available for projects requiring independent verification.
Understanding ERW Weld Integrity and Grade Selection
The ERW welding process produces a consistent longitudinal seam with uniform heat-affected zone properties — suitable for structural applications where seam integrity matters more than the extreme pressures handled by seamless pipe. Steel grade selection follows project specification: Gr.B serves general structural framing, S355 provides higher yield strength for loaded columns, and STK400 meets Japanese architectural standards. Surface treatment choice depends on environment — bare or varnished for interior dry conditions, galvanized for outdoor exposure, black painted for balanced corrosion protection and cost.
The Hidden Cost of Unverified Material
Accepting ASTM A500 welded square steel tube without original mill test certificates risks structural rejection during inspection — forcing full replacement at multiplied cost. Off-grade material passing as S355 may fail load testing under actual service conditions, while missing CE documentation delays customs clearance for European shipments. [NEED_CITE: structural steel certification requirements for construction projects]
Procurement Confidence from Source to Site
Our Jinan facility runs three ERW production lines with monthly capacity exceeding 20,000 tons, covering 2,800+ specifications across square tubes, round pipes, plates, and section steel. Every ASTM A500 welded square steel tube ships with original mill test certificates documenting chemical composition and mechanical properties. We maintain ready stock for standard sizes, support custom orders with flexible MOQ from 5 tons, and provide professional container loading optimization — because a 20ft load of square tubes with crushed corners teaches you that stowage matters as much as the mill cert.
Documentation & Compliance
- Mill test certificate documenting Gr.B and S355 chemical composition and yield strength per ASTM A500
- CE certificate covering EN 10210/EN 10219 for European market structural compliance
- ISO 9001:2015 quality management certification for production traceability
- SGS or BV third-party inspection report available upon request for project verification
- Material traceability by heat number linking each ASTM A500 welded square steel tube to production batch
- Complete customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Square tubes bundled with steel strips and edge protectors to preserve surface treatment during ocean transit
- Galvanized ASTM A500 welded square steel tube packaged with moisture barriers to prevent white rust formation
- Container loading optimized for 6m and 12m lengths with custom stowage drawings for maximum payload
- Plain ends protected with plastic caps to prevent damage and maintain dimensional accuracy
- Heat number and steel grade marked on each bundle for site identification and traceability
- FOB, CIF, and DDP shipping options with professional export documentation handling
Getting Your Quote and Mill Certificates
Submit your specifications including size, wall thickness, steel grade, quantity, and destination port to receive competitive pricing with volume discounts. We respond within 12 hours with quotation, delivery timeline, and sample mill test certificate for quality verification.
Request Your ASTM A500 Welded Square Steel Tube Quote
Send your specifications via email or WhatsApp to receive factory-direct pricing with original mill test certificates and third-party inspection options.
Contact: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Email: admin@sdxinjiyuan.com
WhatsApp: +86 188 5315 7756
