Description
Factory-Direct Galvanized Hollow Sections — Q235 and Q345 rectangular tubes ship straight from our Jinan mill with EN 10219 and ASTM A53 compliance documentation, eliminating trading company markups on every ton.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square and Rectangular Steel Tube |
| Product Type | Square / Rectangular Steel Tube (Galvanized Hollow Section) |
| Steel Grade | Q235, Q345, S235JR, S275JR, STK400, STK500, SGCC, CGCC, DX51D |
| Standard | GB/T 3091, BS 1387, EN 39, EN 1139, ASTM A53, JIS G3444, EN 10204/3.1B |
| Section Shape | Square / Rectangular |
| Size Range | 21.3–3048 mm |
| Wall Thickness | 0.8–50 mm |
| Length | Random / Fixed / SRL / DRL / Customized (up to 12000 mm) |
| Technique | Hot Rolled Based / ERW |
| Surface Treatment | Pre-painted galvanized (Zn 60–120 g/m²), Hot-dipped galvanized (Zn 120–500 g/m²), Electroplated galvanized (Zn 10–50 g/m²) |
| Tolerance | ±5% |
| Ends | Plain end / Beveled end / Threaded end |
| Coating | Z30–Z40 (Regular Spangle) |
| Hardness | Full Hard |
| Skin Pass | Yes |
| Oiled or Non-oiled | Slightly Oiled |
| Processing Service | Bending, Welding, Decoiling, Cutting, Punching |
| Application | Steel structure projects, Low pressure liquid delivery, Scaffolding, Construction frames, Container plates |
| MOQ | 5 tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Steel structure frames for industrial plants and warehouses |
| Construction Companies | Scaffolding systems and building support columns |
| Infrastructure Developers | Bridge handrails and highway sound barrier structures |
| Machinery Manufacturers | Equipment bases and conveyor support frames |
| Municipal Engineering | Low-pressure water and gas distribution pipelines |
Where Galvanized Coating Weight Determines Project Lifespan on Site
Hot-dipped zinc at 500 g/m² outlasts electroplated coatings by decades in corrosive environments — choosing wrong means premature rust and structural replacement.
Global buyers sourcing galvanized hollow sections from fragmented suppliers face specification gaps that standard catalogs cannot cover. A 60 g/m² pre-galvanized tube specified for a coastal scaffolding project will show white rust within months, while the same application demands hot-dipped coating at 275 g/m² minimum. Certification risks compound the problem — missing EN 10219 mill test certificates cause customs delays at EU ports, forcing re-shipment or local sourcing at triple the cost. [NEED_CITE: hot-dip galvanizing coating thickness standards for structural steel]
Matching Zinc Coating Options to Corrosive Environments
Galvanized square and rectangular steel tubes arrive at job sites with three distinct coating strategies. Electroplated finish at 10–50 g/m² suits indoor applications where aesthetic appearance matters more than corrosion resistance — display racks and interior partitions. Pre-painted galvanized at 60–120 g/m² handles moderate outdoor exposure for signage frames and light structural supports. Hot-dipped galvanizing at 120–500 g/m² covers the heavy-duty spectrum: coastal construction, chemical plant structures, and municipal infrastructure where salt spray or industrial atmosphere demands decades of protection without maintenance.
Structural Compliance and Certification Requirements for Galvanized Hollow Sections
Engineering specifications for galvanized hollow sections reference EN 1993-1-1 for European projects and AISC 360 for North American construction, both requiring documented material properties traceable to heat numbers. Q235 and Q345 grades from Chinese mills meet S235JR and S355JR equivalence under EN 10219 when certified through third-party inspection. The ±5% wall thickness tolerance ensures theoretical weight calculations match actual delivered tonnage, preventing budget overruns on large-volume orders. CE certification under EN 10210/10219 becomes mandatory for structural applications in EU member states, while SGS or BV inspection reports satisfy Middle East and Southeast Asian procurement requirements. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections certification requirements]
Steel Grade Selection and Galvanizing Process Fundamentals
Q235 remains the workhorse grade for general construction frames across Asia and Africa, offering adequate strength at competitive pricing. Q345 steps up for load-bearing columns and beam systems where higher yield strength reduces section sizes. S235JR and S275JR serve European projects requiring EN standard compliance with guaranteed impact toughness at sub-zero temperatures. STK400 and STK500 target Japanese-specification projects for architectural exposed structures. The ERW welding process produces consistent seam quality across the 21.3–3048 mm size range, while hot-rolled base material ensures uniform zinc adhesion during galvanizing. Wall thickness from 0.8 mm handles light gauge framing up to 50 mm for heavy structural applications, with the galvanizing bath penetrating internal surfaces on open-ended sections.
Hidden Costs of Incorrect Galvanized Tube Procurement
Material substitution without documentation triggers rejection during structural inspection — a 50-ton order of electroplated tubes delivered as hot-dipped creates rework costs exceeding the original purchase price. Missing mill test certificates delay customs clearance for weeks, demurrage charges accumulating daily at destination ports. Negative tolerance beyond specification means actual wall thickness falls below design requirements, forcing engineering recalculation or complete replacement. Coating weight misrepresentation surfaces only after installation when premature corrosion appears, voiding warranty claims and damaging contractor reputation. [NEED_CITE: steel grade equivalence between GB, EN, and ASTM standards]
Why Procurement Teams Choose Our Galvanized Hollow Section Supply
Factory-direct pricing eliminates trading company margins on every container shipped from Jinan. Our in-house physical and chemical laboratory conducts incoming material inspection, in-process monitoring, and final verification before shipment — every heat number traceable from coil to finished tube. The 2,800+ specification range covers side lengths up to 3048 mm and wall thicknesses to 50 mm, eliminating the need to source standard and non-standard sizes from separate suppliers. Fourteen years of export experience across 50+ countries means documentation packages arrive complete: CE certificates for EU customs, SGS reports for Middle East projects, BV verification for Southeast Asian infrastructure. Custom cutting, bending, and punching services reduce on-site fabrication time, while professional loading plans optimize container utilization for the 12-meter length range.
Documentation & Compliance
- Mill test certificate documenting Q235 and Q345 chemical composition and mechanical properties per GB/T 3091 and EN 10204/3.1B
- CE certificate confirming EN 10210/10219 compliance for structural hollow sections exported to European Union member states
- ISO 9001:2015 quality management system certificate covering production processes and inspection procedures
- SGS or BV third-party inspection report verifying coating weight, dimensions, and surface quality for project-specific requirements
- Material traceability documentation linking each tube bundle to heat number and production batch records
- Customs clearance package including packing list, bill of lading, and certificate of origin for destination port requirements
Packaging, Loading & Delivery
- Galvanized tubes bundled with steel strips and edge protectors to preserve zinc coating integrity during ocean transit
- Slightly oiled surface treatment prevents white rust formation on electroplated and pre-painted finishes during storage and shipping
- Container loading plans optimized for 21.3–3048 mm section sizes, maximizing payload within 20-foot and 40-foot high-cube configurations
- Custom cutting to fixed lengths up to 12000 mm reduces on-site waste and handling requirements for construction projects
- Heat number and steel grade marked on each bundle for site identification and quality traceability verification
- FOB, CIF, and DDP shipping options with door-to-door logistics coordination for 50+ countries across EU, North America, and Asia-Pacific regions
Initiating Your Galvanized Hollow Section Procurement
Submit your specification requirements — section dimensions, wall thickness, steel grade, quantity, and destination port — via email or WhatsApp to receive detailed quotation within 12 hours. Request mill test certificates and coating weight verification reports before contract signing to confirm compliance with your project standards. Our engineering team provides custom loading plans and non-standard size consultation for specifications outside the 2,800+ standard range.
Request Galvanized Tube Quotation with Mill Test Certificate
Send your specifications to admin@sdxjysteel.com or contact via WhatsApp at +86 188 5315 7756 for pricing and documentation confirmation.
Frequently Asked Questions
Q: What is the difference between hot-dipped, pre-galvanized, and electroplated coating options?
A: Hot-dipped galvanizing immerses finished tubes in molten zinc at 120–500 g/m² coating weight for maximum corrosion resistance in outdoor and industrial environments. Pre-painted galvanized applies zinc at 60–120 g/m² with additional organic coating for moderate exposure conditions. Electroplated finish deposits zinc at 10–50 g/m² through electrical process, suitable for indoor applications requiring aesthetic appearance.
Q: Can you provide steel grade equivalence between Q235/Q345 and European EN standards?
A: Q235 meets S235JR requirements under EN 10219 for general structural applications, while Q345 corresponds to S355JR with higher yield strength for load-bearing members. Mill test certificates document chemical composition and mechanical properties confirming equivalence. Third-party inspection through SGS or BV verifies compliance for EU projects requiring CE certification.
Q: What is the minimum order quantity and can you produce non-standard sizes?
A: Minimum order quantity is 5 tons per specification. Our production lines cover 2,800+ standard specifications with side lengths up to 3048 mm and wall thicknesses to 50 mm. Custom non-standard sizes outside this range are available through dedicated production scheduling with typical lead times confirmed upon order placement.
Q: How do you ensure coating weight meets project specifications?
A: In-house laboratory conducts coating weight testing on every production batch using magnetic thickness gauges and gravimetric methods per EN ISO 1461. Hot-dipped galvanizing targets 120–500 g/m² based on customer requirements, with results documented in mill test certificates. Third-party inspection reports from SGS or BV provide independent verification for project-specific quality requirements.
Q: What documentation do you provide for EU customs clearance?
A: CE certificate under EN 10210/10219 confirms structural hollow section compliance for European Union import requirements. Mill test certificates per EN 10204/3.1B document material properties traceable to heat numbers. Complete customs package includes packing list, bill of lading, certificate of origin, and commercial invoice formatted for destination port requirements.
