Description
Factory-direct supply with full traceability — Every SPCC and DC01 hot dip galvanized square and rectangular steel tube ships with an original mill test certificate showing zinc coating weight and heat number.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Hot Dip Galvanized Welded Square / Rectangular Steel Tube |
| Product Type | Galvanized Square / Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | SPCC, DC01, DC02, DC03, DC04 |
| Standard | JIS, DIN, ASTM |
| Section Shape | Square / Rectangular |
| Size Range | 20×20mm – 200×200mm |
| Wall Thickness | 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 / Machinery / Scaffolding / Furniture / Fluid transport |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction | Building frames, column supports, roof trusses, curtain wall sub-frames |
| Infrastructure | Highway guardrail posts, bridge handrails, street light poles |
| Scaffolding | Scaffold ledger tubes, vertical standards, base plates |
| Machinery | Conveyor frames, equipment guard structures, machine bases |
| Furniture | Display racks, warehouse shelving, industrial workbench frames |
| Steel Structures | Warehouse purlins, mezzanine beams, portal frame bracing |
What Missing Zinc Coating Data Costs on a Galvanized Tube Order
A galvanized square or rectangular tube without verified coating weight is a corrosion liability waiting to fail.
Buyers ordering hot dip galvanized square and rectangular steel tube for outdoor structures often discover too late that the zinc layer is paper-thin — 15g/m² sold as 60g/m², rust bleeding through within one monsoon season. Worse, the mill test certificate lists “galvanized” without specifying coating class, leaving no contractual basis for a claim. On scaffolding and marine-adjacent frames, this means premature replacement, safety inspection failures, and project delays that dwarf the original material savings. [NEED_CITE: hot dip galvanizing coating thickness standards per ASTM A123]
Matching Galvanized SHS and RHS to Structural and Corrosive Environments
Hot dip galvanized square and rectangular steel tube in SPCC and DC01 grades delivers reliable corrosion protection for construction frames, scaffolding, and machinery supports where painting is impractical. The zinc coating of 30–275g/m² covers environments from indoor warehouse shelving to coastal guardrails, with heavier coatings specified for industrial or marine exposure. ERW welding produces a clean weld seam that accepts galvanizing uniformly, avoiding the bare spots common on poorly prepared black tube. Each Hot Dip Galvanized Square / Rectangular Steel Tube Supplier order is matched to the project’s corrosion category before coating weight is locked.
Engineering Compliance and Certification Requirements
Galvanized SHS and RHS used in load-bearing frames must conform to dimensional tolerances that satisfy structural design codes, and the ±1% tolerance on these tubes supports compliance with common engineering specifications for non-critical structural members. For projects entering the EU, CE marking under EN 10219 or EN 10210 becomes a customs and site-acceptance requirement — a missing certificate can hold an entire container at the port. [NEED_CITE: EN 10219 cold-formed welded structural hollow sections requirements] Steel grade selection between SPCC and the DC01–DC04 series should align with the forming complexity of the connection detail, as deeper drawing grades reduce cracking risk at welded corners. Original mill test certificates with heat number traceability are essential for inspector sign-off on pressure-adjacent or safety-critical assemblies.
Steel Grade, Welding Process, and Galvanizing Explained
SPCC and the DC01 through DC04 series are low-carbon cold-rolled grades optimized for forming and welding rather than high structural strength — they suit light to medium frames, furniture, and scaffolding where ductility and surface finish matter more than yield class. ERW (electric resistance welding) forms the tube from strip and produces a consistent longitudinal seam that galvanizes cleanly when the weld flash is removed before dipping. Hot dip galvanizing immerses the finished tube in molten zinc, metallurgically bonding the coating to the steel surface; coating weight from 30g/m² serves indoor dry environments, while 275g/m² handles industrial or humid outdoor exposure. Wall thickness tolerance of ±1% means that a 2.0mm nominal tube will measure between 1.98mm and 2.02mm — critical when calculating load capacity and connection fit-up on precision frames. [NEED_CITE: steel grade equivalence between JIS G3466 SPCC and EN 10219 grades]
Hidden Costs of Buying the Wrong Galvanized Tube
Specifying a lighter zinc coating than the environment demands leads to rust-through within months, triggering full replacement and structural re-inspection. Tolerance abuse — tubes consistently at the negative edge of ±1% — reduces actual load capacity and causes fit-up gaps at welded connections, forcing on-site rework. Missing or forged mill test certificates mean the batch cannot be traced to its heat, failing inspector approval and blocking customs clearance on regulated projects. [NEED_CITE: mill test certificate requirements for structural steel imports]
Why Engineers Source Galvanized SHS and RHS From Us
Every Hot Dip Galvanized Square / Rectangular Steel Tube Supplier claim is backed by an original mill test certificate showing chemical composition, mechanical properties, and zinc coating weight — not a generic “galvanized” stamp. Our factory-direct model eliminates trader margins on volume orders of 5 tons and above, with sizes from 20×20mm to 200×200mm held in ready stock for fast dispatch. Custom cutting to 6m, 6.4m, or 12m lengths is performed in-house, with dimensional reports provided before shipment. ISO 9001:2015 and CE certification, plus SGS or BV third-party inspection, satisfy both quality management and destination-country compliance. Professional heavy-cargo loading on flatbeds and open-top containers prevents zinc coating damage from friction and edge contact during ocean transit.
Documentation & Compliance
- Mill test certificate documenting SPCC or DC01 chemical composition, yield strength, and zinc coating weight per JIS / DIN / ASTM standards
- CE certificate confirming compliance with EN 10219 for structural hollow sections where required by destination market
- ISO 9001:2015 quality management certificate covering the galvanizing and welding process
- SGS or BV third-party inspection report available before shipment for project-critical orders
- Full material traceability by heat number linking each tube to its original coil and galvanizing batch
- Export customs documents including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Galvanized tubes bundled with steel strips and edge protectors to preserve the zinc coating during handling and ocean transit
- Seaworthy packaging with waterproof wrapping for 6m, 6.4m, and 12m lengths, optimized for 20ft and 40ft open-top container loading
- Plain ends capped or wrapped to prevent zinc damage and moisture ingress at the tube interior
- Heat number and steel grade (SPCC / DC01) stenciled on each bundle for site identification and inspector verification
- FOB, CIF, and DDP shipping terms available, with professional flatbed and break-bulk options for oversized rectangular sections
- Custom cut-to-length service available before galvanizing, with dimensional tolerance report included
Requesting a Quote for Your Galvanized SHS / RHS Project
Submit your required steel grade (SPCC, DC01–DC04), section size, wall thickness, length, zinc coating class, and destination port to receive a detailed quotation with mill test certificate preview and typical production lead times. Non-standard sizes, cut-to-length, and third-party inspection requirements are confirmed before the proforma invoice is issued.
Get Your Galvanized Tube Quote With Mill Test Certificate
Send your specification list and destination to receive pricing, coating confirmation, and export documentation details.
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
