Description
Factory-Direct Supply, No Middleman Markup — We roll, galvanize, and ship S235, S275, SS400 galvanized square and rectangular steel tubes from our own mill line, so every heat number traces back to a single slab.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S235 S275 SS400 Galvanized Square and Rectangular Steel Tube |
| Product Type | Square / Rectangular Steel Tube (SHS/RHS) |
| Steel Grade | S235, S275, SS400, 20# |
| Standard | JIS, ASTM A53 |
| Section Shape | Square / Rectangular |
| Size Range | Customized |
| Length | 6 m / 12 m (customizable) |
| Technique | Hot-dip Galvanizing |
| Surface Treatment | Hot-dip Galvanized |
| Tolerance | ±1% |
| Ends | Plain / Beveled / Threaded / Grooved |
| Processing Service | Welding / Punching / Cutting / Bending |
| Application | Steel structures / Construction frames / Machinery parts / Fluid transport / Scaffolding |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Steel Fabricators | Structural frames, equipment support bases, truss bracing |
| Construction Companies | Scaffolding uprights, building frameworks, curtain wall sub-frames |
| Machinery Manufacturers | Machine bases, hydraulic cylinder housings, conveyor structures |
| Infrastructure Projects | Highway guardrail posts, sound barrier columns, lighting pole bases |
When Coating Weight Becomes the Real Specification
A 60-micron zinc layer is what keeps a scaffold tube from rusting through before the next inspection cycle.
On every galvanized square steel tube supplier order we receive from Southeast Asian EPCs, the first question is never about size — it is about zinc coating weight and whether it meets the project’s corrosion category. Buyers often receive pre-galvanized tubes quoted as hot-dip, and the coating peels within one monsoon season. Traceability gaps make it impossible to prove which coil the tube came from when the consultant rejects the batch. [NEED_CITE: hot-dip galvanizing coating thickness standards for structural hollow sections]
Matching the Right Grade to the Load Path
S235, S275, and SS400 galvanized square steel tubes cover the full range of non-alloy structural framing. S235 handles light-duty bracing and scaffolding where deflection governs the design, while S275 steps up for medium-load portal frames and machinery bases. SS400, aligned with JIS G3101, is the default for Japanese-spec infrastructure projects across Southeast Asia. Each grade is available in both square and rectangular sections, with hot-dip galvanizing applied after forming so the zinc coat covers the weld seam and corner radii uniformly.
Structural Codes, Corrosion Categories, and Customs Paperwork
Load-bearing frames designed to EN 1993 or AISC 360 require documented yield strength and traceable heat numbers — a mill test certificate is not optional, it is the first document the site engineer asks for. [NEED_CITE: EN 10219 cold-formed hollow section requirements] Hot-dip galvanizing to ISO 1461 or ASTM A123 determines whether the tube survives C3, C4, or C5 corrosion environments, and the coating class must match the project specification before shipping. For EU-bound orders, CE marking under EN 10219 is a customs clearance prerequisite; for North America, ASTM A53 compliance governs the same role. Our galvanized square steel tube supplier line ships with full dimensional inspection reports and third-party SGS or BV certificates attached to each bundle.
Why Hot-Dip Beats Pre-Galvanized for Structural Use
Hot-dip galvanizing immerses the finished tube in molten zinc at around 450°C, creating a metallurgical bond that covers every surface — including the interior of closed sections — with a coating thicker and more adhesive than electro-galvanized or pre-galvanized alternatives. The ±1% dimensional tolerance ensures that field-cut connections and bolted joints fit without reaming. Plain, beveled, threaded, or grooved ends are available so the tube arrives site-ready for welding, mechanical coupling, or flange connection. S235 and S275 grades maintain ductility after the galvanizing thermal cycle, which matters when the fabricator needs to punch or bend on site.
The Hidden Cost of Buying the Wrong Coating
Specifying pre-galvanized when the project calls for hot-dip does not save money — it shifts the cost to the site, where rejected batches mean crane downtime, re-procurement lead times, and potential structural re-inspection. [NEED_CITE: corrosion protection requirements for structural steel in coastal environments] Missing heat-number traceability on a galvanized square steel tube supplier order can halt customs clearance or fail a consultant’s audit, turning a routine delivery into a demurrage bill. Negative tolerance abuse on wall thickness reduces both load capacity and zinc coverage at the corners, where stress concentrates first.
Why Project Buyers Choose Our Mill Line
We operate the galvanizing bath and the tube forming line under one roof, so every heat number on the mill test certificate matches the coil we started with — no re-melt, no mixed batches. Our理化实验室 tests every heat for chemical composition and mechanical properties before the tube enters the zinc bath, and we hold ISO 9001:2015 certification plus CE marking for EN 10219 compliance. With over 2,800 stock specifications in S235, S275, and SS400, we fill mixed-size container orders that smaller mills reject, and our loading team builds every 40-foot container around the actual tube length and weight to avoid zinc-coating abrasion during ocean transit. Custom cutting to 6 m or 12 m, plus beveled or grooved ends, ships in the same bundle — no secondary processing subcontractor in the chain.
Documentation & Compliance
- Mill test certificate documenting S235, S275, or SS400 chemical composition and yield strength per ASTM A53 or JIS standards
- CE certificate confirming EN 10219 compliance for structural hollow sections entering EU markets
- ISO 9001:2015 quality management certificate covering the full forming and galvanizing process
- SGS or BV third-party inspection report verifying zinc coating thickness and dimensional tolerance before shipment
- Full material traceability by heat number from raw coil to finished galvanized tube
- Complete customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- S235 and S275 galvanized square and rectangular tubes bundled with steel strips and edge protectors to preserve the zinc coating at corner radii during ocean transit
- Hot-dip galvanized surface protected by anti-abrasion separators between layers, preventing zinc scratch damage in 6 m and 12 m lengths
- Container loading optimized by our logistics team to balance weight distribution and avoid overweight penalties on 40-foot open-top or flat-rack shipments
- Custom cut-to-length service available for 6 m or 12 m定尺, with beveled, threaded, or grooved ends packed separately by specification
- Heat number and steel grade stenciled on each bundle for site-level traceability and inspector verification
- FOB, CIF, and DDP shipping terms available with full export documentation and door-to-door tracking
Start Your Procurement With Verified Specifications
Submit your required steel grade (S235, S275, SS400), section dimensions, length, quantity, and destination port — we respond within 12 hours with a detailed quotation, zinc coating specification, and sample mill test certificate. For non-standard sizes or custom end processing, our engineering team provides a cut-to-size方案 with dimensional drawings before production begins.
Request Your Galvanized Square Steel Tube Quote With Full Mill Test Certificate
Send your specification sheet to admin@xjyplate.com or contact us via WhatsApp at +86 188 5315 7756. We will return a formal quotation with coating weight confirmation, third-party inspection options, and estimated production lead time within one working day.
Frequently Asked Questions
Q: What is the difference between S235, S275, and SS400 grades for galvanized square tubes?
A: S235 and S275 are European standard grades (EN 10025) with increasing yield strength, commonly used in structural frames and machinery bases. SS400 is a Japanese standard grade (JIS G3101) widely specified in Southeast Asian infrastructure projects. All three are available as hot-dip galvanized square and rectangular tubes with full mill test certificates.
Q: Can you provide mill test certificates and third-party inspection reports?
A: Yes. Every galvanized square steel tube shipment includes an original mill test certificate documenting chemical composition and mechanical properties by heat number. SGS or BV third-party inspection is available before shipment to verify zinc coating thickness, dimensional tolerance, and surface quality.
Q: What is the MOQ for customized sizes and lengths?
A: The minimum order quantity is 1 Ton. We accept mixed-size orders within a single container, and custom lengths of 6 m or 12 m are available with plain, beveled, threaded, or grooved ends.
Q: How does hot-dip galvanizing compare to pre-galvanized coating?
A: Hot-dip galvanizing immerses the finished tube in molten zinc, creating a metallurgical bond with thicker, more durable coating coverage — including the interior of closed sections and weld seams. Pre-galvanized tubes are made from pre-coated coil and have thinner zinc at the weld seam and cut edges, making hot-dip the preferred choice for structural and outdoor applications.
Q: What are the loading and shipping options for heavy galvanized tubes?
A: We ship via flatbed truck, open-top container, or break-bulk vessel depending on order volume and destination. Our loading team optimizes weight distribution to avoid container overweight penalties and uses edge protectors to preserve the galvanized coating during transit. FOB, CIF, and DDP terms are available.
Get Your Certified Galvanized Square Steel Tube Quote Today
Email your project specifications to admin@xjyplate.com or message us on WhatsApp at +86 188 5315 7756. We will provide a detailed quotation with mill test certificate sample, zinc coating confirmation, and shipping schedule within 12 hours.
