Description
Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier
Direct Mill Supply, Full Traceability — Every Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier shipment leaves with original mill test certificates, heat-number traceability, and CE documentation ready for customs clearance at destination port.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q345 Galvanized Rectangular Steel Tube |
| Product Type | Galvanized Rectangular Steel Tube (Square / Rectangular Hollow Section) |
| Steel Grade | Q235, Q235B, Q345, Q345B, SS400, Q195–Q460, SS330–SS540 |
| Standard | ASTM, API, CE, JIS, ISO 9001 |
| Section Shape | Square / Rectangular / Round |
| Wall Thickness | 0.5–200 mm |
| Length | 6 m / 6.4 m / 12 m (or custom required) |
| Technique | Cold Rolled / Hot Rolled / Zinc Coated (Hot Dipped Galvanized) |
| Surface Treatment | Galvanized (Silver Colour) / Consumer’s Requirement |
| Tolerance | ±1% |
| Ends | As per customer requirement |
| Application | Construction structures / Bridges / Railways / Ships / Vehicles / Machinery manufacturing / Petrochemical industry / Marine development / Fluid transport / Offshore oil fields |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Structural frames, bridge support columns, building skeleton beams, scaffolding uprights |
| Petrochemical & Marine | Offshore platform handrails, pipeline support racks, fluid transport piping, deck grating frames |
| Machinery & Vehicle Manufacturing | Equipment base frames, chassis cross-members, conveyor structures, crane boom sections |
| Shipbuilding & Railways | Ship deckhouse framing, railway carriage underframes, ballast tank stiffeners |
What Galvanized Coating Weight Decides Before the First Weld
A missing or thin zinc layer turns a 20-year structural member into a 2-year rust problem.
I have watched entire container loads of rectangular tubes get rejected at destination because the galvanizing shop cut corners on coating thickness. The buyer only found out when a third-party inspector scraped the surface and measured zinc below the specified threshold. Re-galvanizing on-site is not an option — the tubes had to be shipped back or written off. Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier production at our facility means every batch goes through the same hot-dip line with controlled bath temperature, immersion time, and withdrawal speed. The result is a metallurgical zinc-iron alloy bond that survives cutting, welding, and field handling without peeling. [NEED_CITE: hot dip galvanizing coating thickness requirements per ASTM A123]
Matching Section Geometry to Structural Load Paths
Rectangular and square hollow sections carry bending loads more efficiently per kilogram than open profiles because the material is distributed away from the neutral axis on all four faces. When a bridge support column faces multi-directional wind and traffic loading, the Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier range from 0.5 mm to 200 mm wall thickness lets engineers choose exactly the section modulus they calculated — nothing over, nothing under. We have supplied 12 m lengths of Q345B rectangular tubes with 10 mm wall thickness to a West African shipyard for gantry crane legs; the fabricator needed tight ±1% tolerance so their pre-drilled connection plates aligned without reaming on-site.
Engineering Compliance Across Continental Standards
Structural projects in Europe require EN 10219 cold-formed hollow sections, while North American specifiers call for ASTM A500 Grade B or C. The Q235/Q345 grades we roll sit cleanly within the GB framework and map to equivalent ASTM and JIS designations, so a single purchase order can serve multi-country EPC contracts. [NEED_CITE: steel grade equivalence between GB Q235 Q345 and ASTM A500 EN 10219] CE marking on our Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier products clears EU customs without additional testing, and SGS or BV third-party inspection can be arranged before loading. Custom lengths at 6 m, 6.4 m, or 12 m reduce on-site welding joints, and our cutting service delivers ready-to-weld blanks with deburred edges.
Steel Grade Selection and the Galvanizing Process
Q235 and Q345 belong to the Chinese GB/T 700 and GB/T 1591 families respectively; Q345 offers higher yield strength for load-bearing frames while Q235 remains the go-to for general structural work where weight savings are less critical. SS400 (JIS G3101) and the SS330–SS540 range cover Japanese-spec projects, and our Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier inventory spans all these grades so buyers do not need to split orders across multiple vendors. Hot dip galvanizing immerses the formed tube in molten zinc at approximately 450 °C, creating a metallurgical bond with the steel substrate. This differs fundamentally from pre-galvanizing (electro-galvanized), where the zinc layer is thinner and mechanically bonded — suitable for indoor use but inadequate for marine splash zones or buried foundations. Wall thickness tolerance of ±1% ensures the theoretical weight used in structural calculations matches the delivered product, avoiding surprise overruns or under-specification that could fail a load test.
The Real Cost of Buying the Wrong Grade or Missing Paperwork
Specifying Q235 when the structural drawing calls for Q345 means the member yields under design load — a failure that only surfaces during commissioning or, worse, under live service. Missing mill test certificates trigger customs holds in markets that enforce CE or ASTM documentation, turning a routine delivery into weeks of demurrage and air-freight replacement costs. Negative tolerance abuse — where the actual wall thickness falls below the nominal value — reduces load capacity silently; the tube looks right but performs below spec. Every Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier order from our mill ships with heat-number-linked MTCs showing chemical composition and mechanical properties, so the inspector at destination can verify the exact batch against the project specification. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed hollow sections]
Procurement Confidence Built on Mill-Level Control
As the dedicated plate and coil division of Shandong Xin Jiyuan Special Steel Tube Co., Ltd, we control the full chain from raw material selection through galvanizing and final bundling. Our in-house laboratory issues original mill test certificates for every heat, and third-party inspection by SGS or BV is arranged before loading at no extra coordination burden on the buyer. The Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier range covers wall thicknesses from 0.5 mm to 200 mm — meaning a single supplier handles both light-gauge purlin sections and heavy-wall structural columns. Custom cutting, leveling, and end preparation are completed at our facility so the tubes arrive on-site ready to weld, eliminating the need for a secondary processor. Professional heavy-cargo loading using flatbed trailers, open-top containers, and break-bulk methods ensures thick-wall rectangular tubes reach the port without edge damage or zinc coating scratches. ISO 9001:2015 certification and CE compliance are standard on every shipment, and grade equivalence guidance between GB, ASTM, and JIS systems is provided during the quotation stage to prevent specification errors before the contract is signed.
Documentation & Compliance
- Mill test certificate documenting Q235/Q345 chemical composition and mechanical properties per GB/T 700 and GB/T 1591, linked to individual heat numbers
- CE certificate confirming Hot Dipped Galvanized Rectangular Steel Tube compliance with EN 10219 cold-formed hollow section requirements for EU market entry
- ISO 9001:2015 quality management certificate covering the full production and galvanizing process
- SGS or BV third-party inspection report available upon request, verifying coating thickness, dimensional tolerance, and surface quality before shipment
- Full material traceability from heat number through galvanizing batch to final bundle identification
- Export customs documents including packing list, bill of lading, and certificate of origin prepared for destination-country clearance
Packaging, Loading & Delivery
- Galvanized rectangular tubes bundled with high-tensile steel strips and edge protectors to preserve the zinc coating during ocean transit and crane handling
- Surface protection maintained through controlled stacking with timber dunnage separators, preventing zinc-to-zinc contact that causes white rust in humid container environments
- Open-top container or flatbed loading optimized for 6 m, 6.4 m, and 12 m lengths of Q235 Q345 rectangular tubes, maximizing payload while staying within port weight limits
- Custom cut-to-length service delivers ready-to-weld blanks at specified dimensions, reducing on-site cutting waste and labor for construction and machinery fabricators
- Bundle labels clearly marked with heat number, steel grade (Q235B/Q345B), section dimensions, wall thickness, and gross/net weight for instant yard identification
- FOB, CIF, and DDP shipping terms available with professional heavy-cargo logistics coordination from Jinan port to destination site
Start Your Quotation with Grade and Dimension Details
Submit your required steel grade, section dimensions, wall thickness, length, quantity, and destination port — our engineering team responds within 12 hours with a detailed quotation including material cost, any cutting or processing fees, and shipping terms. For non-standard sizes or mixed-grade project orders, we provide a consolidated specification-matching report so you can confirm compliance before placing the deposit. Mill test certificates and CE documentation are confirmed at the quotation stage, not after the contract is signed.
Request Your Hot Dipped Galvanized Rectangular Steel Tube Q235 Q345 ASTM CE Supplier Quotation
Send your specification sheet or drawing to receive pricing, lead time, and mill test certificate samples for your project review.
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
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
