Description
Factory-direct SHS/RHS supply — Q235 and Q345 galvanized square and rectangular tubes rolled to your wall-thickness and length call, shipped with original mill certificates.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square / Rectangular Steel Tube |
| Product Type | Square / Rectangular Steel Tube (SHS/RHS) |
| Steel Grade | Q195, Q215, Q235, Q345, S235, S355, GR.A, GR.B |
| Standard | ASTM A213, DIN EN 10217-1 |
| Section Shape | Square / Rectangular |
| Size Range | Wall thickness 0.8 – 30 mm; Length 0.1m – 11.8m |
| Technique | Welded (ERW) / Seamless options |
| Surface Treatment | Pre-galvanized / Hot-dipped galvanized / Bare / Oiled / Black |
| Tolerance | ±1% |
| Ends | Plain / Beveled per order |
| Application | Steel fence, steel post, warehouse and building construction, structural pipe |
| MOQ | 10 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Structural frames, steel posts, warehouse portal frames |
| Fencing & Security | Perimeter fencing, gate posts, anti-climb barriers |
| Steel Fabrication | Cut-to-length sections for workshop welding and assembly |
| Building Construction | Roof trusses, mezzanine beams, column supports |
Where Negative Tolerance Eats Your Structural Budget on a Galvanized Square Steel Tube Order
A ±1% wall-thickness claim means nothing if the mill runs the lower bound on every piece.
Procurement teams ordering galvanized square steel tube for structural frames often discover the damage only at the fabrication stage: weld prep reveals thinner-than-specified walls, galvanizing inspectors flag coating weight below spec, and the engineer’s load calculation no longer holds. [NEED_CITE: EN 10219 cold-formed hollow section tolerance requirements]. When tubes arrive with forged or missing mill test certificates, the entire batch fails traceability — and customs holds the container before the zinc coating ever sees salt air.
Matching Wall Thickness and Coating to Fence and Frame Environments
A C350 fence post in West Africa needs a different coating strategy than a Q235 warehouse purlin in Southeast Asia. Hot-dipped galvanizing delivers thicker zinc for coastal or industrial atmospheres, while pre-galvanized strip-formed tubes suit indoor structural frames where appearance and cost matter more than decades of corrosion resistance. As a Galvanized Square Steel Tube Supplier, we map coating weight to environment before quoting — not after the container lands.
Structural Code Compliance and Grade Equivalence Across Borders
Engineering specs written to EN 10219 or ASTM A500 rarely match Chinese GB/T 6728 grade names one-to-one. Q235 roughly aligns with S235JR; Q345 tracks S355J2 — but chemical composition and impact-test temperature differ, and a customs officer in Rotterdam will not accept a handwritten equivalence note. [NEED_CITE: steel grade equivalence between EN and ASTM standards]. We supply original MTCs showing heat number, chemistry, and mechanical properties against the standard your engineer specified, so the tube clears both the port and the site inspector.
Decoding Q-Series, S-Series, and ERW Weld Integrity
Q195 and Q215 serve light-duty fencing where forming matters more than load; Q235 and Q345 carry structural frames and warehouse columns with higher yield strength. S235 and S355 follow the European naming convention, with the number indicating minimum yield in MPa and trailing letters (JR, J2) defining Charpy impact energy at sub-zero temperatures. ERW welding produces a continuous longitudinal seam suited to square and rectangular profiles; the weld zone is normalized during galvanizing, restoring ductility across the corner radius. [NEED_CITE: ERW weld line treatment in cold-formed hollow sections]. Wall thickness from 0.8 mm covers light gauge fencing, while 30 mm sections handle heavy structural columns — and the ±1% tolerance applies across that full range.
The Hidden Cost of Unverified Coating Weight and Forged Certificates
A shipment of Q345 RHS labeled as hot-dipped but carrying only 275 g/m² zinc will rust through within two years in a marine environment — yet the invoice says “HDG compliant.” Worse, if the MTC heat number does not match the stencil on the tube, the engineer cannot sign off, the building inspector rejects the frame, and demolition costs multiply. [NEED_CITE: galvanized coating weight verification per ISO 1461]. Sourcing from a Galvanized Square Steel Tube Supplier who issues traceable, third-party-verifiable certificates eliminates this risk before the deposit clears.
Why Project Buyers Source Galvanized Square Steel Tube From XJY Plate
We operate from Jinan’s steel logistics corridor, where every container we load has passed through our own weighing bridge and coating-thickness gauge. Our mill test certificates carry the original heat number, chemical composition, and yield strength — verifiable by SGS or BV at the loading port. With over 2,800 stock specifications in SHS and RHS, we consolidate fence posts, structural columns, and purlin sections into a single container plan, reducing your freight cost per ton. Custom cutting to 0.1m – 11.8m lengths happens in-house, so your site crew receives ready-to-weld pieces, not scrap-generating 12-meter bars. Professional flatbed and open-top container loading ensures the zinc coating survives transit without edge damage.
Documentation & Compliance
- Mill test certificate documenting Q235 or Q345 chemical composition, yield strength, and elongation per GB/T 6728 or EN 10219 as specified
- CE certificate covering EN 10219 cold-formed welded structural hollow sections for EU-bound shipments
- ISO 9001:2015 quality management certificate valid across all SHS/RHS production lines
- SGS or BV third-party inspection report verifying zinc coating thickness, dimensional tolerance, and surface quality
- Full material traceability by heat number stenciled on each tube and cross-referenced on the MTC
- Export customs package: packing list, bill of lading, certificate of origin, and fumigation certificate where required
Packaging, Loading & Delivery
- Q235 and Q345 galvanized tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Hot-dipped galvanized SHS/RHS wrapped in waterproof cloth for containers; bare or oiled tubes shipped with rust-preventive paper interleaving
- 11.8m maximum length loaded in open-top containers or on flatbed trailers with timber dunnage to prevent corner crushing
- Cut-to-length service from 0.1m to 11.8m reduces on-site waste and fits smaller fabrication shop layouts
- Each bundle labeled with heat number, steel grade, section dimensions, and wall thickness for site-level traceability
- FOB, CIF, and DDP terms available; door-to-door logistics to Southeast Asia, Middle East, Africa, and South America
Request a Quote With Mill Test Certificate Attached
Send your section dimensions, wall thickness, steel grade, coating type, and destination port — we return a detailed quotation with the corresponding MTC template and a loading plan within 12 hours. For non-standard lengths or custom punching and bending, our processing team confirms feasibility and lead time before you commit.
Frequently Asked Questions
Q: What is the difference between pre-galvanized and hot-dipped galvanized square tubes?
A: Pre-galvanized tubes are formed from already-coated steel strip, giving a thinner but uniform zinc layer suited to indoor or mild environments. Hot-dipped galvanizing immerses the finished tube in molten zinc, producing a thicker coating for outdoor, coastal, or industrial corrosion resistance.
Q: Can Q235 be used as an equivalent to S235JR or ASTM A36?
A: Q235 shares similar yield strength with S235JR and A36, but chemical composition and impact-test requirements differ by standard. We supply MTCs showing the exact chemistry and mechanical properties so your engineer can verify compliance.
Q: Is it possible to order cut-to-length galvanized square tubes below the 10-ton MOQ?
A: Yes — if the required sections match our current stock sizes, we can consolidate smaller orders into a shared container. Custom cutting, punching, and bending services are available for project-specific fabrication needs.
Q: How do you verify the galvanized coating thickness meets specification?
A: We measure coating weight using a magnetic thickness gauge at multiple points on each tube and can arrange SGS or BV third-party inspection at the loading port to certify compliance with ISO 1461 or your project specification.
Q: What is the invoicing method — theoretical weight or actual weight?
A: We invoice by theoretical weight based on the specified dimensions and steel density, with a ±1% tolerance on wall thickness, ensuring transparent and predictable costing for your project budget.
Get Your Galvanized SHS/RHS Quote With Full Traceability
Submit your section size, steel grade, coating requirement, and destination — we reply within 12 hours with pricing, mill test certificates, and a container loading plan.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjyplate.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjyplate.com
