Description
Factory-Direct Pricing, No Middlemen — Every SPCC and DC01–DC04 hot dip galvanized square and rectangular steel tube ships straight from our Jinan production lines, cutting procurement costs for structural frame and scaffolding buyers.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Hot Dip Galvanized Square / Rectangular Steel Tube |
| Product Type | Square / Rectangular Steel Tube |
| Steel Grade | SPCC, DC01, DC02, DC03, DC04 |
| Standard | JIS, DIN, ASTM |
| Section Shape | Square / Rectangular |
| Size Range | 20×20mm – 200×200mm |
| Wall Thickness | 0.5 – 200mm (standard 1.0–6.0mm) |
| Length | 1 – 12m (6m, 6.4m, 12m available) |
| Technique | Welded (ERW) |
| Surface Treatment | Hot Dip Galvanized (Zinc Coating 30–275g/m²) |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures, construction frames, fluid transport, machinery, scaffolding, furniture, greenhouse, fencing |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding systems, structural supports for EPC projects |
| Machinery Manufacturing | Equipment frames, conveyor structures, precision tube assemblies |
| Agricultural & Industrial | Greenhouse frames, fencing systems, fluid transport pipelines |
Zinc Coating Weight Decides Whether Your Galvanized Tubes Survive the Job Site
Hot dip galvanized square and rectangular steel tubes with zinc coating below 60g/m² will corrode through within months in humid or coastal environments — no amount of repainting fixes a failed substrate.
I’ve watched containers of galvanized tubes arrive at Middle Eastern ports where third-party inspectors rejected the entire shipment because the zinc layer measured 25g/m² instead of the contracted 120g/m². The supplier had quoted electro-galvanized pricing while claiming hot dip quality. Buyers who don’t verify zinc coating weight against mill test certificates end up paying twice — once for the cargo, once for the replacement. [NEED_CITE: hot dip galvanizing coating thickness standards per ASTM A123]
Matching SPCC and DC01–DC04 Grades to Structural and Fabrication Demands
Hot dip galvanized square and rectangular steel tubes in SPCC and DC01–DC04 grades deliver the formability that construction frames and scaffolding systems require. DC03 and DC04 offer deeper drawing capability for punched and bent connections, while SPCC handles general structural framing where moderate forming is involved. Our ERW welding process produces consistent seam integrity across the 20×20mm to 200×200mm range, and the hot dip galvanizing bath coats both exterior and interior surfaces uniformly — critical for greenhouse structures and fencing exposed to continuous moisture.
Engineering Compliance and Certification Requirements for Galvanized Hollow Sections
Structural applications demand compliance with recognized hollow section standards. Our hot dip galvanized square and rectangular steel tubes meet JIS, DIN, and ASTM specifications, and we hold CE certification under EN 10210/EN 10219 for European market access. The ±1% tolerance on wall thickness and dimensions ensures that load calculations remain valid — negative tolerance beyond specification limits compromises structural integrity and fails engineering inspections. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections dimensional tolerances] Third-party verification through SGS and BV provides independent confirmation that zinc coating, chemical composition, and mechanical properties meet declared standards before shipment leaves the factory.
Understanding SPCC and DC01–DC04 Steel Grades in Galvanized Tube Production
SPCC is a commercial-quality cold-rolled steel grade widely used in general-purpose structural applications, offering balanced strength and weldability. The DC01 through DC04 series represents progressively higher formability levels — DC01 suits simple bending and cutting, DC02 handles moderate forming, DC03 supports deep drawing operations, and DC04 provides the highest elongation for complex fabrication. All grades undergo hot dip galvanizing with zinc coating from 30g/m² for indoor furniture applications up to 275g/m² for heavy industrial and outdoor structural use. The ERW welding technique produces a clean seam that accepts galvanizing without coating discontinuity, and the ±1% dimensional tolerance keeps weight calculations predictable for procurement and logistics planning.
Hidden Costs of Purchasing Galvanized Tubes Without Verified Coating and Certification
Buying galvanized square and rectangular tubes based on price alone without confirmed zinc coating weight and mill test certificates creates downstream failures. Coating below specification corrodes prematurely, forcing premature replacement on active construction sites. Missing CE or EN certification blocks customs clearance in European markets, stranding cargo at port with demurrage charges accumulating daily. Wall thickness exceeding negative tolerance limits reduces load-bearing capacity and fails structural engineering review. [NEED_CITE: consequences of substandard galvanized coating on corrosion resistance]
Procurement Advantages of Direct Factory Supply
Our Jinan facility operates three dedicated production lines covering over 2,800 specifications, including custom non-standard sizes beyond published catalogs. Every heat of SPCC and DC01–DC04 steel passes through our in-house physical and chemical laboratory before galvanizing, generating original mill test certificates with full traceability by heat number. We hold 41 invention patents including proprietary sharp-corner rectangular tube technology, and our CE EN 10210/EN 10219 certification alongside ISO 9001:2015, SGS, and BV verification eliminates documentation gaps that delay international shipments. Professional loading plans optimize container utilization for 6m and 12m lengths, and we coordinate FOB, CIF, and DDP delivery to over 50 countries.
Documentation & Compliance
- Mill test certificate documenting SPCC and DC01–DC04 chemical composition and mechanical properties per JIS and ASTM standards
- CE certificate confirming compliance with EN 10210 and EN 10219 for European structural hollow section requirements
- ISO 9001:2015 quality management system certificate covering production and inspection processes
- SGS or BV third-party inspection report verifying zinc coating thickness and dimensional accuracy
- Material traceability documentation linking each bundle to heat number and production batch
- Complete customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Hot dip galvanized SPCC and DC01–DC04 tubes bundled with steel strips and edge protectors to preserve zinc coating integrity during ocean transit
- Seaworthy packaging with waterproof wrapping for 6m and 12m lengths, preventing surface damage from moisture condensation in containers
- Professional loading optimization for 20×20mm to 200×200mm sections, maximizing container payload for 5-ton minimum orders
- Custom cutting to project-specified lengths within the 1–12m range, reducing on-site waste and secondary processing
- Heat number and steel grade markings stenciled on each bundle for site identification and inspection traceability
- FOB, CIF, and DDP shipping options with door-to-door logistics coordination to construction sites across 50+ countries
Starting Your Galvanized Tube Procurement
Submit your specifications including section dimensions, wall thickness, steel grade preference, zinc coating requirement, quantity, and destination port to receive a detailed quotation with production timeline and applicable certification documentation. We provide original mill test certificates and third-party inspection reports for quality confirmation before production begins, and our team coordinates custom non-standard sizes and professional loading plans for your project requirements.
Frequently Asked Questions
Q: What is the difference between hot dip galvanized and electro-galvanized square tubes, and which offers better corrosion resistance?
A: Hot dip galvanizing immerses steel tubes in molten zinc, producing a metallurgically bonded coating from 30g/m² to 275g/m² that covers all surfaces including interior weld seams. Electro-galvanizing applies zinc electrolytically, yielding thinner coatings typically below 60g/m² with limited interior coverage. Hot dip galvanized square and rectangular steel tubes provide superior corrosion resistance for outdoor structural, scaffolding, and greenhouse applications.
Q: Can you provide custom non-standard sizes and what is the MOQ for special specifications?
A: Our production lines cover over 2,800 specifications including custom non-standard dimensions beyond the published 20×20mm to 200×200mm range. The standard MOQ is 5 tons, and we accommodate special size requests with typical production lead times confirmed upon specification review.
Q: How do you ensure zinc coating thickness consistency and what testing methods are used?
A: Our in-house physical and chemical laboratory tests zinc coating weight on every production batch using magnetic thickness gauges and gravimetric methods per ASTM standards. Original mill test certificates document coating measurements, and we arrange SGS or BV third-party inspection for independent verification before shipment.
Q: What certifications do you provide for EU/US customs clearance and project compliance?
A: We supply CE certification under EN 10210 and EN 10219 for European markets, ISO 9001:2015 quality system certification, and complete customs documentation including mill test certificates, packing lists, bills of lading, and certificates of origin. Third-party inspection reports from SGS and BV are available for project-specific compliance requirements.
Q: What is the production lead time and do you offer DDP delivery with professional container loading optimization?
A: Typical production lead times are confirmed upon order placement based on specifications and quantity. We provide FOB, CIF, and DDP shipping options with professional loading plans that optimize container utilization for 6m and 12m tube lengths, coordinating door-to-door logistics to project sites across 50+ countries.
Request Your Hot Dip Galvanized Square and Rectangular Steel Tube Quotation
Send your specifications, steel grade requirements, and destination details to receive pricing, mill test certificates, and delivery timelines within 12 hours.
Email: admin@sdxjysteel.com | WhatsApp: +86 188 5315 7756 | Tel: +86 531 8573 6315
