What is a galvanized square tube?
Hot-dip galvanized square tubing is a steel product featuring a zinc coating applied to the surface of a square steel tube through a hot-dip galvanizing process, thereby significantly enhancing its corrosion resistance. Combining the structural strength of square tubing with the protective benefits of a zinc coating, it is widely utilized in fields such as construction, machinery, and energy.
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Weight Calculation Formula
The theoretical weight per meter (kg/m) is calculated as follows:
4 × Wall Thickness (mm) × (Side Length (mm) − Wall Thickness (mm)) × 0.00785
Example: 50 × 50 × 5 mm Square Tube → Weight per meter ≈ 7.33 kg
Galvanized Square Tube Specifications Table
| Product name | Galvanized Steel pipe/tube |
| OD | 10-600mm(round) |
| thickness | 1.2-30mm as customers' requirements |
| length | 3-12m or as customers' requirements |
| Shape | Round , square, other shape |
material |
Q195-Grade B, SS330, SPC, S185 Q215-Grade C,CS Type B, SS330, SPHC Q235---Grade D, SS400, S235JR, S235JO, S235J2 Q345---SS500, ST52 |
| Standard | GB/T13793-1992,GB/T14291-2006, GB/T3091-1993,GB/T3092-1993,GB3640-88 BS1387/1985,ASTM A53/A36,EN39/EN10219,GB/T9711.1-99 etc |
| zinc coating | pre galvanized steel pipe: 60-150g/m2 hot dipped galvanized steel pipe:200-400g/m2 |
| application | Widely used in Structure, Accessorize,Construction, Fluid transportation,machinery parts,the stress parts of the automobile tractor parts and so on |
Package |
1) Big OD: in bulk 2) Small OD: packed by steel strips 3) Plastic bags 4) According to customer's requirement |
| Delivery | Normally 7-20 days after get deposits or according to quantity |
| Certification | ISO 9001-2008 BV TUV SGS |
advantage |
1. reasonable price with excellent quality 2, abundant stock and prompt delivery 3, rich supply and export experience, sincere service |
Material Chemical Composition (%)
| Grade | Element/Property | Specification |
|---|---|---|
| Q195 | C | 0.06-0.12 |
| Mn | 0.25-0.50 | |
| Si | ≤0.30 | |
| S | ≤0.050 | |
| P | ≤0.045 | |
| Tensile strength | 315-430 (Mpa) | |
| Yield strength | 195 (Mpa) | |
| Elongation | 33 | |
| Q235 | C | 0.12-2.0 |
| Mn | 0.3-0.70 | |
| Si | ≤0.30 | |
| S | ≤0.045 | |
| P | ≤0.045 | |
| Tensile strength | 375-460 (Mpa) | |
| Yield strength | 235 (Mpa) | |
| Elongation | 26 | |
| Q345 | C | ≤0.20 |
| Mn | ≤1.70 | |
| Si | ≤0.55 | |
| S | ≤0.040 | |
| P | ≤0.040 | |
| V | 0.02-0.15 | |
| Tensile strength | 470-630 (Mpa) | |
| Yield strength | 345 (Mpa) | |
| Elongation | 2 |
Hot-Dip Galvanized vs Cold Galvanized Square Pipe
| Comparison Item | Hot-Dip Galvanized Square Pipe | Cold Galvanized Square Pipe |
|---|---|---|
| Production Method | Molten zinc immersion process (high-temperature hot-dip) | Electroplating / cold electro-galvanizing (room temperature) |
| Zinc Coating Thickness | 30–270 g/m² (thick and uniform) | 10–30 g/m² (very thin) |
| Coating Adhesion | Extremely strong, not easy to peel off | Weak, easy to scratch or fall off |
| Corrosion Resistance | Excellent, suitable for outdoor & humid environments | Basic, only for indoor or dry environments |
| Rust Prevention Life | 10–30 years (depending on environment) | 1–5 years, short service life |
| Surface Appearance | Slightly rough, typical spangle pattern | Smooth, bright, good cosmetic effect |
| Inside & Outside Coating | Full coverage inside and outside | Often only outside; poor internal protection |
| Price Level | Higher cost, high cost-performance | Lower price, economical for short-term use |
| Main Applications | Construction structure, guardrails, outdoor pipelines, agricultural engineering, marine environment | Indoor decoration, temporary structures, light non-load-bearing parts, interior pipelines |
| Weldability | Good, suitable for structural welding | Limited, easy to damage coating during welding |
Packaging and Shipping
FAQ
Which is better for outdoor use: hot-dip or cold galvanized square pipe?
Hot-dip galvanized is far better for outdoor, humid, or corrosive environments.
Why is hot-dip galvanized more expensive?
Thicker zinc layer, higher process cost, and longer service life.
Can cold galvanized pipe be used for construction structures?
Not recommended; it has low strength and poor rust resistance.
How long does hot-dip galvanized square pipe last?
Normally 10–30 years, depending on zinc coating and environment.
Can you customize size and zinc layer thickness?
Yes, we support full customization of size, length, and zinc coating.
Case Studies
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