ASTM A500 Zinc-Coated Structural Hollow Sections For Construction, Solar And Infrastructure Projects
Product Description
Galvanized Square Tubes and Rectangular Hollow Sections (RHS/SHS) are high-strength structural steel products designed to deliver superior corrosion resistance and long-term durability in demanding environments. Manufactured from premium carbon steel and protected with a zinc coating through hot-dip galvanizing or pre-galvanizing processes, these tubes provide an ideal balance between strength, service life, and cost efficiency.
Compared with ordinary black steel tubes, galvanized hollow sections require less maintenance and offer significantly longer protection against rust, making them suitable for both indoor and outdoor applications.
These products are widely used in steel structures, commercial buildings, photovoltaic mounting systems, transportation infrastructure, agricultural facilities, and industrial fabrication projects.
Cause
Structural steel is often exposed to challenging environmental conditions such as:
- Rain and humidity
- Industrial pollution
- Coastal salt spray
- Temperature fluctuations
- Chemical exposure
Without adequate surface protection, steel tubing can corrode rapidly, resulting in reduced structural performance, increased maintenance costs, and shortened project life cycles.
As modern construction projects demand longer service life and lower maintenance requirements, traditional untreated steel tubing is no longer sufficient for many applications.
Solution
Galvanized square and rectangular tubes solve these challenges through a protective zinc coating that shields the steel substrate from corrosion.
Key Benefits
- Outstanding corrosion resistance
- Extended service life
- Reduced maintenance costs
- High structural strength
- Excellent weather resistance
- Easy fabrication and installation
- Cost-effective long-term investment
The zinc layer not only acts as a physical barrier but also provides sacrificial protection, helping prevent rust even if minor surface damage occurs.
Product Specifications
| Parameter |
Details |
| Material |
Q195, Q235B, Q355B (or equivalent) |
| Size range |
20x20mm, 25x25mm, 30x30mm, 40x40mm, 50x50mm, 60x60mm, 80x80mm, 100x100mm, 150x150mm, 200x200mm |
| Wall thickness |
1.0mm – 5.0mm (custom available) |
| Length |
6m, 5.8m, or customized (max 12m) |
| Zinc coating thickness |
45µm – 90µm (as per ASTM A123 / EN ISO 1461) |
| Standard |
ASTM A500, EN 10219, GB/T 6728 |
| Surface treatment |
Hot dip galvanized, smooth and bright |
| Tolerance |
According to international standard |
Available Surface Options
- Hot-Dip Galvanized (HDG)
- Pre-Galvanized (GI)
- Custom Zinc Coating Requirements
Application
Structural Construction
- Steel building frames
- Roof support systems
- Warehouse structures
- Commercial buildings
Fencing & Security
- Perimeter fencing
- Security barriers
- Gate frames
- Guardrail systems
Renewable Energy
- Solar panel support structures
- Ground-mounted PV systems
- Renewable energy facilities
Industrial Manufacturing
- Machine frames
- Equipment supports
- Production line structures
Public Infrastructure
- Bridges and walkways
- Airport projects
- Municipal facilities
- Transportation engineering
How It Works
Galvanized steel tubes are protected through a two-stage corrosion defense mechanism.
Barrier Protection
The zinc coating forms a protective shield that prevents moisture, oxygen, and corrosive substances from reaching the steel surface.
Cathodic Protection
When the coating is scratched or damaged, zinc corrodes before steel due to its electrochemical properties. This sacrificial protection helps maintain the integrity of the underlying metal and significantly extends service life.
This dual-protection system is the primary reason galvanized tubing outperforms ordinary carbon steel in outdoor environments.
How To Choose
Selecting the correct galvanized hollow section depends on project requirements.
For Light-Duty Applications
Recommended Size:
- 20*20 mm to 80*80 mm
- Thickness: 1.0–3.0 mm
Suitable For:
- Fencing
- Greenhouses
- Decorative structures
For Medium Structural Projects
Recommended Size:
- 100*100 mm to 200*200 mm
- Thickness: 3.0–8.0 mm
Suitable For:
- Warehouses
- Workshops
- Commercial buildings
For Heavy Structural Applications
Recommended Size:
- 250*250 mm and above
- Thickness: 8.0–16.0 mm
Suitable For:
- Industrial plants
- Infrastructure projects
- Large steel structures
Key Selection Factors
- Environmental conditions
- Load-bearing requirements
- Zinc coating thickness
- Service life expectations
- Budget considerations
Products Display
FAQ
Q1: What is the difference between hot-dip galvanized and pre-galvanized tubes?
Hot-dip galvanized tubes are coated after fabrication, resulting in a thicker zinc layer and superior corrosion resistance. Pre-galvanized tubes are manufactured from galvanized steel strips and are generally more economical.
Q2: Are galvanized square tubes suitable for outdoor use?
Yes. Hot-dip galvanized square tubes are specifically designed for outdoor applications and provide excellent protection against weather-related corrosion.
Q3: What standards are available for galvanized hollow sections?
Common standards include ASTM A500, ASTM A36, EN 10219, BS standards, JIS standards, and GB standards.
Q4: Can galvanized rectangular tubes be customized?
Yes. Customized sizes, lengths, wall thicknesses, zinc coating weights, and fabrication services can be provided according to project requirements.
Q5: Why are galvanized hollow sections preferred for solar mounting systems?
Their excellent corrosion resistance, high strength, and low maintenance requirements make them ideal for long-term outdoor solar installations.
Q6: What is the expected service life of galvanized steel tubing?
Depending on the environment and zinc coating thickness, galvanized tubing can provide reliable corrosion protection for 20–50 years or more.