Description
Vertically Integrated Galvanized SHS/RHS Manufacturer — Own steel mill and fabrication facility delivering Q195 Q235 Q345 hot dipped galvanized square and rectangular steel tubes with full material traceability from raw coil to finished section.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q195 Q235 Q345 Hot Dipped Galvanized Square Rectangular Steel Tube |
| Product Type | Square / Rectangular Galvanized Steel Tube (SHS / RHS) |
| Steel Grade | Q195, Q235, Q345 |
| Standard | BS EN, GB, AISI, ASTM, DIN, JIS |
| Section Shape | Square / Rectangular |
| Size Range | Side length 10 mm – 1000 mm |
| Wall Thickness | 0.6 – 28 mm |
| Length | 1 – 12 m |
| Technique | ERW (Hot Rolled / Cold Rolled) |
| Surface Treatment | Hot Dipped Galvanized (Zinc Coating 30 – 275 g/m²) |
| Ends | Plain / Beveled / Threaded with Couplings or Sockets |
| Application | Steel structures / Construction frames / General fabrication / Manufacturing / Frames / Trailers / Bridge and highway construction / Industrial equipment / Machine parts / Sign posts / Agricultural equipment |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC & General Contractors | Structural steel frames for industrial buildings and warehouses, portal frame systems, mezzanine platforms |
| Infrastructure & Civil Engineering | Bridge handrail posts, highway gantry supports, sound barrier columns |
| Agricultural & Rural Construction | Greenhouse structural frames, livestock shed columns, irrigation support structures |
| Industrial Manufacturing | Equipment base frames, conveyor support structures, machine guarding frames |
| Signage & Outdoor Structures | Highway sign post systems, lighting pole bases, billboard support frames |
What Zinc Coating Weight Actually Determines on a Galvanized Tube Order
The difference between 30 g/m² and 275 g/m² is not a price negotiation — it is the boundary between 5 years and 30 years of corrosion resistance in the same environment.
Overseas buyers sourcing Hot Dipped Galvanized Square Rectangular Steel Tube from trading companies frequently discover coating inconsistency only after arrival at site. A trader may quote 60 μm but ship tubes with 35 μm on internal corners where zinc flow is restricted during hot dipping. When those tubes are installed in a coastal warehouse frame or a Middle East highway gantry, premature rust appears within months — and the replacement cost dwarfs the original material saving. [NEED_CITE: hot dip galvanizing coating thickness standards ASTM A123]
How Q195 Q235 Q345 Hot Dipped Galvanized Square Rectangular Steel Tube Matches Structural Frame Requirements
Hot dipped galvanized SHS and RHS in Q235 and Q345 grades serve as primary load-bearing members in portal frame warehouses and industrial buildings across Southeast Asia and the Middle East. The combination of ERW seam integrity and zinc coating 30–275 g/m² provides both structural continuity and long-term atmospheric corrosion protection without additional painting. Our own steel mill produces the raw ERW tubes and hot dips them in-house, meaning every heat number on the mill test certificate traces back to our casting and rolling lines — no third-party sourcing gaps.
Engineering Compliance and Certification for Galvanized Hollow Sections
Structural engineers specifying galvanized square and rectangular tubes for load-bearing frames require compliance with EN 10210 (hot finished) or EN 10219 (cold formed) for European projects, and ASTM A500 / A53 for North American markets. The Q-series grades Q195, Q235, and Q345 correspond broadly to S235 and S355 in the EN system, and our production documentation includes cross-reference tables for customs and engineering approval. [NEED_CITE: steel grade equivalence between Chinese GB and European EN standards] Third-party inspection by SGS or BV is available before shipment, and CE marking under EN 1090-1 is provided for structural components entering the EU market. Dimensional tolerances follow EN 10219 for cold-formed sections, covering out-of-square, twist, and wall thickness variation.
Steel Grade Selection and ERW Process for Galvanized SHS/RHS
Q195 serves light-duty applications such as greenhouse frames and signage posts where forming ease matters more than load capacity. Q235 is the workhorse grade for general construction frames and scaffolding, offering balanced weldability and strength. Q345 provides higher yield strength for bridge supports and heavy industrial structures where section size optimization reduces overall steel tonnage. The ERW welding process produces a continuous longitudinal seam that, after hot dip galvanizing, becomes fully covered by the zinc layer — eliminating the exposed weld line vulnerability found in some pre-galvanized tubes. [NEED_CITE: ERW weld seam quality requirements in galvanized hollow sections]
Hidden Costs of Sourcing Galvanized Tubes Without Verified Coating and Grade
Purchasing Hot Dipped Galvanized Square Rectangular Steel Tube based on price alone often leads to three categories of hidden cost: zinc coating below specification causing early corrosion and repainting; steel grade substitution where Q195 is shipped instead of Q345, reducing load capacity and triggering engineering re-approval; and wall thickness at the lower end of negative tolerance, increasing the number of tubes required per ton and raising installation labor cost. [NEED_CITE: consequences of negative tolerance in structural steel procurement]
Why XJY Structure Delivers Verified Galvanized SHS/RHS from a Single Source
Our vertically integrated operation — own steel mill producing ERW tubes plus in-house hot dip galvanizing line — eliminates the material traceability gap that plagues trader-sourced orders. Every bundle carries heat number markings linked to our mill test certificates, and our 2,800+ specification inventory means standard sizes ship from stock while custom dimensions are produced to order. We hold CE certification under EN 10210 and EN 10219, ISO 9001 quality management, and routinely facilitate third-party inspection by SGS, BV, or TÜV for clients requiring independent verification. Our professional loading team handles oversized and heavy galvanized bundles with edge protectors to preserve zinc coating integrity during ocean transit, and we provide complete export documentation including certificate of origin, packing list, and bill of lading for smooth customs clearance.
Documentation & Compliance
- Mill Test Certificate documenting Q195, Q235, or Q345 chemical composition and mechanical properties per GB/T 9711 or EN 10204 3.1 format
- CE certificate confirming compliance with EN 10210 for hot finished or EN 10219 for cold formed hollow sections
- ISO 9001 quality management certificate covering the full production chain from steelmaking to galvanizing
- SGS or BV third-party inspection report verifying zinc coating thickness, dimensional tolerances, and visual quality before shipment
- Material traceability by heat number stamped on each tube, linked to the corresponding mill test certificate
- Complete customs documentation including packing list, bill of lading, and certificate of origin for destination country clearance
Packaging, Loading & Delivery
- Hot dipped galvanized square and rectangular tubes bundled with steel strips and edge protectors to prevent zinc coating damage during handling and ocean transit
- Zinc coating 30–275 g/m² preserved by avoiding direct contact between galvanized surfaces and bare steel strapping, using rubberized separators at contact points
- Container loading optimized for side lengths up to 1000 mm and lengths up to 12 m, with nested configurations for smaller SHS/RHS sizes to maximize 20ft and 40ft container utilization
- Custom cutting to site-specific lengths within the 1–12 m range available, reducing on-site waste and cutting labor for EPC projects
- Heat number and steel grade (Q195 / Q235 / Q345) marked on each tube bundle for site identification and traceability verification
- FOB, CIF, and DDP shipping terms available with professional oversized cargo loading plans for heavy-wall and large-section galvanized tubes
How to Initiate a Galvanized SHS/RHS Inquiry for Your Project
Share your project drawings or specification list including steel grade (Q195 / Q235 / Q345), section dimensions, wall thickness, length, zinc coating requirement, and destination port — we respond within 24 hours with a detailed quotation covering material, fabrication, coating, packing, and shipping costs. For non-standard sizes or custom end treatments, our engineering team provides shop drawing confirmation and production scheduling before contract signing.
Frequently Asked Questions
Q: What is the difference between Q195, Q235, and Q345 steel grades for galvanized tubes?
A: Q195 offers the lowest yield strength and highest formability, suitable for light structures like greenhouse frames. Q235 is the standard structural grade for general construction and fabrication. Q345 provides higher yield strength for heavy-load applications such as bridge supports and industrial crane beams.
Q: How does hot dipped galvanizing compare to pre-galvanized coating in corrosion resistance?
A: Hot dipped galvanizing produces a metallurgically bonded zinc-iron alloy layer with coating weights from 30 to 275 g/m², offering significantly longer corrosion protection than pre-galvanized (sendzimir) coating, especially at cut edges and weld zones.
Q: Can you produce non-standard sizes and what is the MOQ for custom dimensions?
A: Yes, we produce custom side lengths from 10 mm to 1000 mm and wall thicknesses from 0.6 mm to 28 mm. The MOQ for standard sizes is 1 Ton; custom dimensions may require higher minimum quantities depending on the production run.
Q: What documentation package do you provide for EU and Middle East customs clearance?
A: We provide CE certificate (EN 10210 / EN 10219), mill test certificate per EN 10204 3.1, ISO 9001 certificate, third-party inspection reports (SGS/BV), and complete export documents including packing list, bill of lading, and certificate of origin.
Q: How do you ensure weld seam quality on ERW galvanized square tubes?
A: Our ERW welding process follows qualified WPS procedures, and the weld seam is fully covered during hot dip galvanizing. In-process ultrasonic testing and post-galvanizing visual inspection verify seam integrity before shipment.
Request a Quotation with Mill Test Certificate
Submit your specification list including steel grade, section size, wall thickness, length, quantity, and destination port — we provide pricing, production lead time, and sample mill test certificates within 24 hours.
Contact: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Tel: +86 531 8573 6315 | Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com | Website: www.xjystructure.com
