Description
Factory-Direct Rectangular GI Tube Supply — SD XJY Pipe manufactures ASTM A500 S355 rectangular GI steel pipes in-house, eliminating trader markups while delivering full mill test documentation for EU and North American projects.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500/A53/S275/S355 Rectangular GI Steel Pipe |
| Product Type | Welded Rectangular Steel Tube (GI) |
| Steel Grade | Gr.B, S235, S275, S355, STK400 |
| Standard | ASTM A500, ASTM A53, GB/T 3091 |
| Section Shape | Rectangular |
| Size Range | 15mm×20mm – 700mm×800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | Welded (ERW) or Seamless |
| Surface Treatment | Hot-dip Galvanized / Black Painting / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Invoicing | By Theoretical Weight |
| Application | Construction structures, building frames, curtain wall structures, support tubes, structural frames, fertilizer tubes |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Building frames, structural columns, roof trusses for warehouses and industrial parks |
| Architectural Facade | Curtain wall support structures, glass facade framing, decorative exterior bracing |
| Infrastructure | Bridge handrails, scaffolding systems, highway sign gantries |
| Industrial Equipment | Machine bases, conveyor supports, fertilizer processing tube frameworks |
Where Zinc Coating Thickness Decides Site Acceptance
A 20-micron shortfall in galvanizing can reject an entire container at destination customs or site inspection.
I still remember a Middle East warehouse facade order where the GI rectangular tubes arrived with 40μm zinc instead of the specified 60μm. The third-party inspector flagged every piece on arrival, and the client had no choice but to reject the full batch. That kind of loss does not come from the steel itself — it comes from trusting a mill that skips in-house coating verification before loading. When buyers source ASTM A500 S355 rectangular GI steel pipe for exposed structural or facade work, inconsistent galvanizing thickness creates rework costs that dwarf the original material savings [NEED_CITE: hot-dip galvanized coating thickness requirements for structural steel].
Beyond coating, specification gaps compound the problem. Projects requiring 700×800mm heavy-wall sections or non-standard lengths often find that most suppliers only stock popular sizes, forcing buyers into fragmented orders from multiple mills — each with different certificates, different tolerances, and different loading quality.
How Hot-Dip Galvanizing Matches Structural and Facade Environments
Hot-dip galvanizing deposits a metallurgically bonded zinc-iron alloy layer that protects rectangular GI tubes against atmospheric corrosion for decades without maintenance. For curtain wall framing and exterior building structures, this means the ASTM A500 S355 rectangular GI steel pipe can be installed directly without additional painting, saving both surface preparation labor and long-term upkeep. Our production lines cover sizes from 15×20mm small-section bracing tubes up to 700×800mm heavy structural members, all galvanized in-line with coating thickness verified before bundling.
Structural Compliance and Certification Requirements
Rectangular hollow sections used in load-bearing frames must conform to dimensional and mechanical requirements set by EN 10219 for cold-formed welded sections or ASTM A500 for cold-formed carbon steel tubing [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerances]. For EU projects, CE marking under EN 10210 (seamless) or EN 10219 (welded) is mandatory for customs clearance — missing or incorrectly referenced certificates will hold cargo at the port. S355 grade selection provides higher yield capacity than S235 or Gr.B, reducing section weight for the same design load, while STK400 serves Japanese-spec projects across Southeast Asia. Fixed-length cutting to 5.8m or 11.8m optimizes container loading and reduces on-site waste.
Steel Grade Equivalence and Welding Process Selection
S235, S275, and S355 represent incrementally higher minimum yield strengths in the EN system, allowing engineers to optimize section size against design loads. ASTM A500 Grade B aligns roughly with S275 in mechanical performance, while STK400 from JIS G3466 serves similar structural roles in Japanese-standard projects. ERW welded production offers cost efficiency for standard wall thicknesses up to 30mm, while seamless options address higher-pressure or critical-load applications. Hot-dip galvanizing after forming ensures full coverage including weld seams, whereas black painted or bare finishes suit indoor or buried applications where corrosion resistance is secondary. The ±1% dimensional tolerance keeps fit-up consistent for bolted and welded connections on site.
The Hidden Cost of Unverified Galvanizing and Missing Certificates
Purchasing ASTM A500 S355 rectangular GI steel pipe based on price alone, without verified coating thickness and valid mill test certificates, exposes projects to three failure modes: zinc coating below specification triggers rejection at third-party inspection; missing CE or EN standard references block EU customs clearance; and negative tolerance beyond acceptable limits reduces actual load-bearing capacity below design assumptions. Each failure mode leads to either cargo return, on-site re-galvanizing, or structural redesign — costs that routinely exceed the initial price difference between a verified supplier and an unverified one [NEED_CITE: consequences of substandard galvanized coating on structural steel].
Why Project Procurement Teams Source From SD XJY Pipe
We operate three dedicated production lines covering over 2,800 specification combinations, meaning your 700×800mm heavy-wall rectangular GI tubes and your 15×20mm bracing sections ship from the same mill under the same quality system. Our in-house physical and chemical laboratory tests every heat for dimensional accuracy, mechanical properties, and zinc coating thickness before loading — the same test that would have caught the 40μm problem I witnessed years ago. We hold 41 invention patents including China’s original sharp-corner rectangular tube technology, CE certification under EN 10210/10219, ISO 9001:2015, and Singapore FPC, with SGS and BV third-party inspection available on request. Custom non-standard sizes, cut-to-length service, and professional container loading with anti-damage measures are standard, not optional extras. We export to over 50 countries, with documented clearance experience across EU, North America, Middle East, and Southeast Asian ports.
Documentation & Compliance
- Mill test certificate documenting S355 chemical composition, yield strength, and zinc coating thickness per ASTM A500 and EN 10219 requirements
- CE certificate of conformity referencing EN 10210 for seamless or EN 10219 for welded rectangular hollow sections, required for EU market import
- ISO 9001:2015 quality management certificate covering full production and testing process at SD XJY Pipe
- SGS or BV third-party inspection report available upon request, covering dimensional, mechanical, and coating verification
- Heat number traceability linking each bundled tube to its original steel coil test report
- Complete customs documentation including packing list, bill of lading, and certificate of origin for destination clearance
Packaging, Loading & Delivery
- Hot-dip galvanized rectangular tubes bundled with steel strips and edge protectors to preserve zinc coating integrity during ocean transit
- Anti-rust oil applied to black painted or bare finish tubes before bundling, preventing surface oxidation during storage and shipping
- Container loading optimized for 5.8m and 11.8m lengths to maximize 20ft and 40ft GP utilization, reducing per-ton freight cost
- Cut-to-length service available for random or fixed lengths, with kerf loss calculated and invoiced by theoretical weight
- Heat number and steel grade stenciled on each tube end for on-site identification and traceability
- FOB, CIF, and DDP shipping terms available from Jinan port, with professional tube and beam loading experience to over 50 countries
Submit Specifications for Quotation and Mill Test Review
Send your rectangular GI tube dimensions, steel grade, surface treatment, quantity, and destination port, and receive a detailed quotation with unit pricing, production lead time, and shipping terms within 12 hours. Request mill test certificates and coating thickness reports before committing, and confirm third-party inspection arrangements if your project requires SGS or BV verification.
Request Your ASTM A500 S355 Rectangular GI Steel Pipe Quotation
Submit specifications via email or WhatsApp to receive pricing, mill test certificates, and delivery schedules.
Email: admin@sdxjypipe.com
Mobile/WhatsApp: +86 188 5315 7756
Frequently Asked Questions
Q: What is the steel grade equivalence between S355, Gr.B, and STK400?
A: S355 (EN), Gr.B (ASTM A500), and STK400 (JIS G3466) serve similar structural roles but differ in yield strength and chemical composition. We provide cross-reference documentation with every quotation to ensure correct material selection for your project standard.
Q: What galvanizing coating thickness do you provide for rectangular GI steel pipes?
A: Hot-dip galvanized rectangular tubes are produced to standard coating thickness requirements, with in-house testing verifying coating before loading. Specific thickness requirements should be confirmed at inquiry stage based on your project environment and specification.
Q: Can you produce non-standard rectangular sizes outside your listed range?
A: Yes. Our production lines cover over 2,800 specifications, and custom non-standard sizes are available with confirmed MOQ. Send your required dimensions for feasibility confirmation and pricing.
Q: Do your rectangular GI pipes carry CE certification for EU import?
A: Yes. Our welded rectangular hollow sections carry CE certification under EN 10219, and seamless options under EN 10210. Full documentation including Declaration of Performance is provided with each shipment.
Q: What is the minimum order quantity for rectangular GI steel pipes?
A: The standard MOQ is 5 tons. For trial orders or specific project requirements, contact us to discuss flexible arrangements.
Get Your ASTM A500 S355 Rectangular GI Steel Pipe Quote Today
Send your specifications, steel grade, and destination port to receive detailed pricing and mill test documentation within 12 hours.
Email: admin@sdxjypipe.com
Mobile/WhatsApp: +86 188 5315 7756
