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Galvanized Round Steel Tube & Galvanized Square Steel Tube: Technical Guide for Industrial Applications

Galvanized steel tubes continue to be the most popular product in carbon steel for the areas of structural engineering, building of infrastructure, and industrial fabrication as a result of their corrosion resistance, mechanical properties and life cost.

From the type of professional security, the galvanized tubes are divided into two main categories only:
Galvanized Round Pipe (Round Steel Tube)
Galvanized Square Steel Tube

Galvanized Steel Pipe The All-Round Player in Construction Projects
galvanized square tube

Galvanized Round Pipe (Round Steel Tube)

A tube which is round in shape can also be known as:
Galvanized round pipe, also known as:
Round steel tube
GI round pipe (Galvanized Iron pipe)
Galvanized round tube
Hot dip galvanized steel pipe
is a CHS (circular hollow section) carbon steel pipe with a layer of zinc on the outside to protect it against corrosion.

The most popular and widely used manufacturing process is hot dip galvanizing, which forms a metallurgical bond between the steel and the zinc layer.

Technical Details

Material Grades
ASTM A53 Grade A/B
ASTM A500 Grade B/C
Q195 / Q235 / Q355
EN 10219

Dimensions
Outside Diameter (OD): 21.3 mm – 325 mm
Wall Thickness: 1.5 mm – 12 mm
Standard Length: 6 m / 12 m / Customized

Zinc Coating
60–120 μm (Hot dip galvanized steel pipe)
40-80 g/m² minimum coating weight (dependent on standard)

Major Advantages
✔ Uniform load distribution
✔ Excellent pressure-bearing capacity
✔ Smooth internal flow performance
✔ Easy threading and welding
✔ Long service life in outdoor environments

Standard Uses
Water & gas distribution
Fire sprinkler systems
Fence posts and guard rails
Scaffolding systems
Agricultural irrigation

For round pipe fluid transfer, GI round pipe is still the most specified galvanized tube in the world.

Galvanized Square Steel Tube

Definition
A square galvanized steel tube is a hollow structural section (HSS) with a square shape, which is galvanized for corrosion protection.
Square tubing offers greater structural integrity and is easier to connect to flats surfaces when compared to round tubing.

Technical Specifications

Material Grades
ASTM A500 Grade B/C
EN 10219
Q235 / Q355

Dimensions
Size: 20×20 mm – 400×400 mm
Wall Thickness: 1.2 mm – 16 mm
Length: 6 m standard or customized

Surface Treatment
Hot dip galvanized
Pre-galvanized (lighter coating for indoor use)

Key Advantages
✔ Superior bending esistance
✔ Improved structural solidness
✔ Easier welding and bolting
✔ Uniform zinc coating coverage
✔ Economical substitute for stainless steel

Typical Applications
Steel structure frames
Warehouses and workshops
Solar mounting systems
Equipment support structures
Prefabricated buildings

Hot Dip Galvanized Steel Pipe vs. Pre-Galvanized Tube

Feature Hot Dip Galvanized Steel Pipe Pre-Galvanized Tube
Coating Thickness 60–120 μm 20–40 μm
Corrosion Resistance Excellent Moderate
Service Life 20–50 years 5–15 years
Application Outdoor & heavy-duty Indoor & light-duty

With the continued growth of global infrastructure investment, demand for high-quality products from reliable galvanized steel pipe suppliers will remain strong. Choosing the right supplier not only ensures product performance but also guarantees project safety, durability, and long-term cost-effectiveness.

Whether your application requires hot-dip galvanized steel pipes for harsh outdoor environments or precision galvanized square steel pipes for structural fabrication, making informed technology choices is crucial for the sustainable development of your project. Royal Steel Group welcomes your inquiries.

ROYAL GROUP

Address

Kangsheng development industry zone,
Wuqing district, Tianjin city, China.

E-mail

sales01@royalsteelgroup.com

Phone

Sales Manager: +8613652091506

Hours

Monday-Sunday: 24-hour Service

Post time: Feb-14-2026