Description
Direct Mill Supply, No Middlemen — Every Q195-Q690 galvanized square and rectangular steel tube rolls off our own cold-forming lines, backed by 41 invention patents and in-house mill test certification before shipment.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square and Rectangular Steel Tube |
| Product Type | Hot-dip Galvanized Square / Rectangular Hollow Section (including sharp-corner RHS) |
| Steel Grade | Q195–Q690, S235JR–S355J2, ASTM A500 Gr.A/B/C/D, JIS G3466 STKR400/490, AS1163 C350/C350L0, 20#, 45# |
| Standard | EN 10219, EN 10210, ASTM A500, JIS G3466, AS1163, GB/T 6728 |
| Section Shape | Square / Rectangular (sharp-corner / right-angle rectangular tube available) |
| Size Range | 250×150 mm, 300×60 mm, and 2,800+ custom specifications |
| Wall Thickness | Up to 40 mm |
| Length | 5.8 m / 6 m / 11 m or custom cut-to-length |
| Technique | Hot-dip Galvanized (ERW base tube) |
| Surface Treatment | Hot-dip Galvanized |
| Tolerance | Per EN 10219 / ASTM A500 dimensional standards |
| Ends | Plain / Beveled / Threaded |
| Application | Steel structures, glass curtain walls, architectural facades, machinery frames, scaffolding, infrastructure projects |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Architectural Facade & Curtain Wall | Sharp-corner galvanized RHS for exposed steel framing in glass curtain wall systems and building envelope structures |
| Steel Structure Fabrication | Column and beam assemblies for commercial buildings, bridges, and Belt & Road infrastructure projects |
| Machinery Manufacturing | Precision galvanized profiles for conveyor frames, industrial equipment bases, and agricultural machinery structures |
| Construction & Scaffolding | Load-bearing scaffolding uprights, temporary support frames, and site infrastructure |
| Infrastructure & Renewable Energy | Support structures for solar mounting systems and utility-scale project frameworks |
Where Sharp-Corner Tolerance Decides Facade Acceptance
Standard ERW rectangular tubes produce rounded corners (R≥2t) that leave visible gaps at mitered joints — a deal-breaker for exposed architectural steel.
Project engineers specifying galvanized square and rectangular steel tube for curtain wall framing routinely discover that generic suppliers cannot hold true right-angle geometry after hot-dip galvanizing. The zinc bath thermal cycle distorts poorly formed corners, turning crisp 90-degree edges into uneven radii. When these tubes reach the job site, facade contractors face re-cutting, re-welding, or outright rejection — costs that rarely appear in the original purchase order. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed hollow sections]
Matching Galvanized RHS to Curtain Wall and Structural Frame Demands
Galvanized square and rectangular steel tube with patented sharp-corner technology delivers the dimensional precision that glass curtain wall contractors require — true 90-degree edges that mate flush at welded or bolted connections without visible gaps. The hot-dip zinc coating (typically 60–80 μm) provides corrosion protection suitable for coastal and high-humidity environments where pre-galvanized alternatives degrade within months. Our cold-forming process holds corner geometry through the galvanizing bath, so the tube arrives at site with the same sharp profile it had leaving the mill.
Engineering Compliance and Certification Requirements
Structural frame applications demand more than physical dimensions — they require traceable certification that satisfies both the engineer of record and customs authorities. Our galvanized square and rectangular steel tube carries CE marking per EN 10210 and EN 10219, which is mandatory for structural steel entering the EU market. [NEED_CITE: CE marking requirements for structural hollow sections under EN 10210] For North American projects, ASTM A500 Gr.B/C compliance ensures compatibility with AISC design specifications. The in-house physical and chemical laboratory tests every heat for composition, yield behavior, and weld integrity before release — data documented in the mill test certificate provided with each shipment.
Steel Grade Selection and Galvanizing Process Explained
The Q-series (Q195–Q690) and S-series (S235JR–S355J2) represent different design philosophies: Q-grades follow Chinese GB standards with yield strength designated by the number (Q355 ≈ 355 MPa yield), while S-grades follow European EN standards with impact toughness specified at sub-zero temperatures (JR = 27J at +20°C, J2 = 27J at −20°C). ASTM A500 Gr.B/C serves the North American market with stricter carbon controls for weldability. Hot-dip galvanizing immerses the formed ERW tube in molten zinc at approximately 450°C, creating a metallurgical bond (zinc-iron alloy layers) that outperforms electro-galvanized coatings in abrasion resistance and edge protection. Wall thickness up to 40 mm requires extended immersion timing to ensure full internal coverage — a process parameter that separates structural-grade galvanizing from light-gauge decorative work.
Hidden Costs of Sourcing the Wrong Galvanized Tube
Purchasing galvanized square and rectangular steel tube without verified mill test certificates creates downstream liabilities that dwarf the initial price saving. Material substitution — receiving Q235B labeled as S355JR — passes visual inspection but fails structural load calculations, triggering engineer rejection and project delays. Missing CE documentation blocks EU customs clearance, stranding containers at port while demurrage charges accumulate. [NEED_CITE: steel grade equivalence between EN 10219 and ASTM A500 standards] Oversized negative tolerance reduces actual wall thickness below design minimums, compromising load capacity without visible indication until failure testing.
Why Project Procurement Teams Source From Our Mill
Our 41 invention patents include China’s first sharp-corner rectangular tube technology — a cold-forming method that produces true right-angle geometry where competitors yield rounded corners. The mill operates 3 dedicated production lines covering 2,800+ specifications, meaning a single purchase order for mixed sizes (250×150, 300×60, custom non-standard) ships from one source with unified certification. Every galvanized square and rectangular steel tube undergoes dimensional, mechanical, and chemical testing in our in-house laboratory before release — no third-party lab delays. Full CE certification per EN 10210/10219, ISO 9001:2015, Singapore FPC, and SGS/BV verification satisfy the most restrictive import markets. Professional container loading with anti-damage measures — steel separators, edge protectors, and bracing — prevents the transit damage that causes field rejection.
Documentation & Compliance
- Mill test certificate documenting Q355B or S355JR chemical composition and mechanical properties per EN 10219, issued per heat number
- CE certificate confirming compliance with EN 10210 (hot-finished) and EN 10219 (cold-formed) for EU structural steel import
- ISO 9001:2015 quality management system certificate covering galvanized hollow section production
- SGS or BV third-party inspection report verifying dimensions, coating thickness, and surface quality before loading
- Material traceability linking each galvanized square and rectangular steel tube to its heat number and production batch
- Complete customs documentation including packing list, bill of lading, and certificate of origin for destination clearance
Packaging, Loading & Delivery
- Hot-dip galvanized tubes bundled with steel strips and separated by rubberized edge protectors to prevent zinc coating abrasion during ocean transit
- Sharp-corner rectangular tubes stacked with wooden cradles at 1.5 m intervals to maintain right-angle geometry under container roof load
- Mixed-size orders (250×150, 300×60, custom) container-optimized with heavy-wall (up to 40 mm) sections loaded at bottom for weight distribution
- Custom cut-to-length (5.8 m / 6 m / 11 m) with bundle tagging showing steel grade, heat number, and piece count per bundle
-唛头 stenciled on each bundle end with project reference, steel grade (e.g., S355J2), and heat number for site identification
- FOB Jinan/Qingdao, CIF destination port, or DDP door-to-door with full export documentation and container tracking
Start Your Procurement With Verified Specifications
Submit your galvanized square and rectangular steel tube requirements — section size, wall thickness, 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 certificate samples, CE documentation, or third-party inspection arrangements before committing to production.
Request a Quote With Mill Test Certificate
Send your specification sheet to admin@sdxjypipe.com or contact via WhatsApp at +86 188 5315 7756 for pricing, certification review, and container loading confirmation.
Frequently Asked Questions
Q: What is the difference between hot-dip galvanized and pre-galvanized square and rectangular tubes?
A: Hot-dip galvanizing immerses the finished tube in molten zinc, creating a thick metallurgical bond (60–80 μm) suitable for outdoor and coastal structural applications. Pre-galvanized tubes are formed from pre-coated steel coil, offering thinner zinc protection (20–30 μm) appropriate for indoor or non-corrosive environments.
Q: Can you produce non-standard sizes outside the 2,800+ specification range?
A: Yes. Custom non-standard sizes are available with low MOQ (1 Ton). Our 3 production lines and in-house tooling shop accommodate special dimensions for architectural facades and machinery frames that fall outside standard catalogs.
Q: Do your galvanized tubes carry CE certification for EU import?
A: All galvanized square and rectangular steel tube products carry CE marking per EN 10210 and EN 10219, with Factory Production Control (FPC) certified by Lloyd’s Register. Complete mill test certificates and Declaration of Performance accompany every EU-bound shipment.
Q: How do you ensure sharp-corner geometry survives the hot-dip galvanizing process?
A: Our patented cold-forming technology (41 invention patents) produces sharp-corner rectangular tubes with controlled corner radius before galvanizing. The forming process accounts for zinc bath thermal distortion, ensuring the tube maintains right-angle geometry after hot-dip coating.
Q: What steel grade equivalents should I specify for international projects?
A: Q355B (GB) ≈ S355JR (EN) ≈ ASTM A500 Gr.B; Q235B (GB) ≈ S235JR (EN) ≈ ASTM A500 Gr.A. Provide your project specification standard, and we confirm the equivalent grade with mill test certificate documentation. [NEED_CITE: international steel grade equivalence tables for structural hollow sections]
Get Your Galvanized Square and Rectangular Steel Tube Quote Today
Submit dimensions, steel grade, quantity, and destination port to receive pricing with full certification documentation within 12 hours.
Contact: admin@sdxjypipe.com | WhatsApp: +86 188 5315 7756
