Galvanized Square Tube 40×40×2.0mm – Ready Stock
Galvanized Square Tube 40×40×2.0mm – Ready Stock
Galvanized square tubes for construction frames, steel structures, fencing, and general fabrication. Available in hot-dip and pre-galvanized finishes, with stable zinc coating and good weldability. Sizes from 20×20mm to 200×200mm, wall thickness 1.0–6.0mm. EN 10204 3.1 MTC can be provided. Contact us for stock, sizes, and factory prices.
- Mill Test Certificate Provided
- Strict Quality Inspection
- Custom Sizes Available
- On-Time Global Delivery
Sky Steel Group supplies hot-dip galvanized (HDG) and pre-galvanized square steel tubes (Square Hollow Sections / SHS) for structural engineering, building framing, agricultural greenhouses, solar mounting systems, and mechanical fabrication. Available in outer dimensions from 15×15 mm to 500×500 mm with wall thicknesses from 0.6 mm to 20 mm, our galvanized square tubes comply with ASTM A500, EN 10219, and JIS G3466 standards.
Forming, Welding & Fabrication
Our galvanized square steel tubes are manufactured using high-frequency ERW welding and cold roll-forming, followed by online weld-seam zinc re-spraying (for pre-galvanized) or full-immersion hot-dip galvanizing. The precision corner radius (R = 1.5t – 2.5t) and uniform wall thickness ensure structural rigidity and seamless joint fit-up.
The tubes support drilling, punching, miter cutting, bending, and arc/MIG welding. The zinc coating provides both barrier shielding and cathodic protection, preventing corrosion at cut edges and welded assemblies exposed to outdoor and industrial environments.
Galvanized Square Tube Specifications
| Item | Available Range |
|---|---|
| Product | Galvanized Square Steel Tube / Hollow Section (SHS) |
| Type | Hot-Dip Galvanized (HDG) / Pre-Galvanized (GI) |
| Standard | ASTM A500 / EN 10219 / EN 10210 / JIS G3466 / GB/T 6728 / AS/NZS 1163 |
| Material Grade | Q195, Q235B, Q355B / S235JRH, S275J0H, S355J2H / ASTM A500 Gr. B/C / STKR400 |
| Outer Dimensions | 15 × 15 mm – 500 × 500 mm / Customized Sizes |
| Wall Thickness | 0.6 mm – 20.0 mm / Strict ±5% to ±8% Tolerance |
| Length | 5.8 m, 6.0 m, 11.8 m, 12.0 m / Precision Cut-to-Length (±2 mm) |
| Zinc Coating Mass | Pre-Galvanized: 40–120 g/m²; Hot-Dip Galvanized: 200–550 g/m² (up to 80 µm) |
| Surface Treatment | Hot-Dip Galvanized / Lightly Oiled / Passivated (Chromated) / Anti-fingerprint |
| End Processing | Clean Square Cut / Deburred / Bevelled / Threaded / Pre-punched Holes |
| Secondary Processing | Laser Tube Cutting / Bending / Punching / Drilling / Flange Welding |
| Application | Building Framework / Scaffolding / Warehouses / Solar Brackets / Highway Guardrails / Machinery |
| Certificate | EN 10204 3.1 Mill Test Certificate (MTC) / CE / ISO 9001 / SGS Inspection |
| Packing | Hexagonal Bundles with High-Tensile Steel Bands / Plastic Caps / Seaworthy Sling Protection |
| Customization | Custom Outer Dimensions / Heavy Wall Thickness / Fixed Length / Custom Hole Punching |
Need a Price for Galvanized Square Tube?
Send us your required dimensions (OD × WT), length, zinc coating weight, steel grade, and quantity for a direct factory quote.
Where Are Galvanized Square Tubes Used?
Galvanized square steel tubes offer high torsional rigidity, uniform strength distribution, and long-term corrosion resistance. They are widely applied across structural engineering, prefabricated construction, industrial workshops, and mechanical framing systems.
Precision Dimensions & Heavy-Wall Structural Sections
Manufactured with tight dimensional tolerances (±0.2 mm on outer dimensions) and clean square corners. The hot-dip galvanized coating covers both internal and external walls with metallurgical bonding, making heavy-wall sections ideal for high-load columns, trusses, and structural load-bearing frames.
On-Site Fabrication, Cutting & Modular Framing
Galvanized square tubes are easy to cut, drill, punch, and weld on construction sites without special pre-heating. Their flat outer faces simplify connection with self-drilling screws, bolted gusset plates, and welded brackets for modular steel structures and light-gauge framing.
Commercial Building Construction & Scaffolding
Used extensively as vertical support columns, perimeter safety barriers, shoring props, and scaffolding systems in multistory building projects. The durable zinc coating resists mechanical impact and weathering during repeated site handling and concrete pouring operations.
Industrial Warehouses & Pre-Engineered Steel Frames
Galvanized hollow sections serve as primary portal frames, secondary purlins, wall girts, and roof trusses for large-span distribution hubs and storage warehouses. The high strength-to-weight ratio minimizes foundation loads while ensuring decades of maintenance-free service.
Export Packaging & Ocean Container Shipping
All export tubes are packed in tight hexagonal bundles strapped with high-tensile steel bands, labeled per heat number, and fitted with waterproof end caps on request. Bundles are loaded with wood dunnage and heavy strapping to prevent shifting during 20ft/40ft ocean container transport.
Frequently Asked Questions About Galvanized Square Tube 40×40×2.0mm – Ready Stock
1. What is the difference between Hot-Dip Galvanized (HDG) and Pre-Galvanized square tube?
The primary difference is the zinc coating thickness and manufacturing process:
• Pre-Galvanized (GI) Tube: Made from pre-galvanized steel strip with an online zinc repair on the weld seam. Zinc coating is typically 40–120 g/m² (5–15 µm). It offers a smoother, brighter surface and is ideal for indoor framing, furniture, and light construction.
• Hot-Dip Galvanized (HDG) Tube: Formed and welded from black steel, then fully immersed in molten zinc at ~450°C. Zinc coating reaches 200–550 g/m² (30–80 µm) inside and out, providing heavy-duty corrosion protection for harsh outdoor, coastal, and chemical environments (25–50+ year service life).
2. What standard sizes and wall thicknesses do you supply?
We supply square sizes from 15 × 15 mm up to 500 × 500 mm and rectangular sizes from 20 × 30 mm up to 400 × 600 mm. Wall thicknesses range from 0.6 mm to 20.0 mm. Standard lengths are 5.8 m (for 20ft container optimization), 6.0 m, 11.8 m, and 12.0 m (for 40ft container optimization), with custom fixed lengths available.
3. Which steel grades and international standards are available?
Our products conform to major international structural standards:
• American Standard: ASTM A500 Grade A, Grade B (most common, min yield 315 MPa), and Grade C (min yield 345 MPa).
• European Standard: EN 10219 / EN 10210 in S235JRH, S275J0H, and S355J2H (high-strength).
• Japanese Standard: JIS G3466 STKR400 and STKR490.
• Chinese Standard: GB/T 6728 Q195, Q235B, and Q355B.
4. Can galvanized square tubes be welded, drilled, and bent?
Yes. Galvanized square tubes can be welded using standard SMAW (stick), GMAW (MIG), or GTAW (TIG) processes. For on-site welding, removing the surface zinc in the immediate weld zone (approx. 20–30 mm) improves arc stability; applying zinc-rich cold galvanizing paint after welding restores full corrosion protection. The tubes can also be bent and pre-punched with CNC machines according to shop drawings.
5. How do you ensure dimensional accuracy and quality consistency?
Every production batch undergoes strict quality control: outer dimension & corner radius verification (caliper/micrometer), ultrasonic weld inspection, hydrostatic pressure testing (where applicable), zinc coating thickness measurement (magnetic/gravimetric method), and tensile/flattening tests. EN 10204 3.1 Mill Test Certificates (MTC) are issued with every order.
6. How are galvanized square tubes packaged for international container shipping?
Tubes are packed in rigid hexagonal bundles bound with high-tensile steel straps (minimum 4–6 bands per 6m bundle) with nylon lifting slings attached for crane unloading. Ends can be protected with plastic caps. Bundles are loaded into 20GP (up to 5.85m) or 40GP/40HQ (up to 11.85m) containers with wooden dunnage to prevent scratching and moisture trapping during sea transit.
