Round steel tubing is a circular, hollow structural section designed to deliver uniform strength, excellent load distribution, and reliable performance in both static and dynamic applications. Its seamless or welded construction provides high resistance to bending, torsion, and impact, making it a preferred choice in construction, fabrication, machinery, and engineering design. With multiple diameters, wall thicknesses, and material options available, round steel tubing offers precise functionality for everything from architectural frames to industrial support systems.

What Is Round Steel Tubing?

Round steel tubing is a circular, hollow steel section used widely in construction, fabrication, manufacturing, and engineering projects. Its smooth round shape and uniform thickness make it strong, lightweight, and easy to work with. Round steel tubing is commonly made from mild steel, carbon steel, or galvanised steel, depending on the environment and application.

Because it provides excellent strength in all directions and resists bending, round steel tubing is one of the most versatile steel products available today.

Benefits of Using Round Steel Tubing

Round steel tubing offers several advantages that make it popular with builders, welders, and fabricators:

1. Strong and Durable

The circular design spreads stress evenly around the tube, giving it strong resistance against bending, twisting, and impact.

2. Lightweight but Strong

Hollow tubes weigh less than solid bars but still offer outstanding load-bearing performance.

3. Easy to Cut, Weld, and Fabricate

Round steel tubing is simple to cut with a saw, weld with MIG/TIG welding, drill, and fit into frames or structures.

4. Clean and Smooth Appearance

Its round shape makes it ideal for visible structures like handrails, gates, and architectural features.

5. Available in Many Sizes and Thicknesses

Builders can choose from thin-wall tubes for light work or thick-wall tubes for heavy-duty industrial applications.

6. Can Be Used Indoors and Outdoors

With galvanised coating or painting, round steel tubing performs well in outdoor environments and coastal areas.

Common Applications of Round Steel Tubing

Round steel tubing is used in many residential, commercial, and industrial projects, such as:

• Handrails, balustrades, and fencing
• Gate and door frames
• Furniture frames and shop fittings
• Automotive and trailer chassis
• Construction and scaffolding components
• Machinery frames and supports
• Exhaust systems and piping
• Sports equipment and playground structures

Because of its versatility, round steel tubing is suitable for both structural and decorative purposes.

Types of Round Steel Tubing

Round steel tubing is available in several material types, each designed for different environments, strength requirements, and fabrication needs. Choosing the right type ensures your project lasts longer, performs better, and stays within budget. Below are the four most common types of round steel tubing, explained with more depth and real-world use cases.

1. Mild Steel Round Tubing

Mild steel round tubing is the most common and cost-effective option. It is made from low-carbon steel, which makes it easy to weld, cut, bend, and drill.

Key advantages:

• Very easy to weld using MIG, TIG, or stick welding
• Affordable and widely available
• Great for indoor or covered environments
• Good balance of strength and flexibility
• Comes in many wall thickness options (thin-wall to heavy-wall)

Typical uses:

• Furniture frames and shop fittings
• Frames for gates, cages, workshops, benches
• Carports and light structures
• Machinery guards and brackets
• DIY projects that require simple fabrication

Mild steel tubing is the go-to choice for general fabrication work.

2. Galvanised Round Steel Tubing

Galvanised round tubing is mild steel coated with zinc to protect it from rust and weathering. The coating forms a barrier that stops moisture, salt, and chemicals from reaching the steel surface.

Key advantages:

• Excellent rust and corrosion resistance
• Ideal for outdoor environments
• Long lifespan even in harsh conditions
• Low maintenance compared to painted steel
• Strong and reliable for structural use

Typical uses:

• Handrails, fences, gates, and balustrades
• Outdoor constructions and playground equipment
• Boat trailers and marine structures
• Outdoor furniture and signage
• Rural fencing and irrigation systems

For any outdoor project, galvanised round steel tubing is usually the safest and most durable option.

3. Stainless Steel Round Tubing

Stainless steel round tubing is used when corrosion resistance, hygiene, and appearance are important. It is more expensive but offers unmatched durability and a clean, polished look.

Key advantages:

• Extremely high corrosion resistance
• Long-lasting even in coastal or chemical environments
• Smooth, polished appearance
• Strong and crack-resistant
• Suitable for environments that require hygiene and sanitation

Typical uses:

• Food and beverage processing
• Marine and coastal structures
• Architectural and decorative handrails
• Medical equipment and laboratory fit-outs
• Luxury furniture and design features

Stainless steel tubing is ideal when you want both performance and aesthetics.

4. Precision Round Tubes (Cold-Drawn Tubing)

Precision round steel tubing, also known as cold-drawn tubing, is manufactured through a cold-forming process that produces a highly accurate, smooth, and consistent tube.

Key advantages:

• Very tight dimensional tolerances
• Smooth internal and external surface finish
• Higher strength due to cold-working
• Perfect for precision-fit assemblies
• Suitable for high-pressure or high-speed applications

Typical uses:

• Hydraulic cylinders and pneumatic systems
• Automotive and mechanical components
• High-precision engineering parts
• Shock absorbers, steering systems, and machine shafts
• Industrial machinery and robotics

If your job requires exact sizing, tight fits, or high-pressure strength, precision tube is the best choice.

5. Round Steel Tubing Sizes (Expanded Guide)

Round steel tubing is defined by three main measurements:

• Outside Diameter (OD) – the width across the tube
• Wall Thickness (WT) – the thickness of the steel
• Length – most commonly 6.0 metres, though custom cuts are available

Understanding these measurements helps you choose the right tubing for both strength and fit.

Round Steel Tubing Sizes

Common Outside Diameters (OD)

Here are some commonly available sizes used in Perth and across Australia:

• 12.7 mm (½”) – light frames, furniture, small projects
• 20 mm – light fabrication, garden frames
• 25.4 mm (1”) – gates, handrails, small structures
• 32 mm – farm gates, medium-strength frames
• 40 mm – fencing, workshop frames
• 48.3 mm – scaffolding, handrails, strong structural use
• 60.3 mm – columns, supports, heavy-duty frames
• 76 mm and above – industrial and structural applications

Large-diameter round tubing is often used in engineering, machinery, and architectural structures.

Common Wall Thicknesses

Round steel tubing is available in:

• 1.6 mm – lightweight
• 2.0 mm – standard fabrication
• 2.5 mm – stronger general use
• 3.0 mm – 4.0 mm – heavy-duty structural use
• 5.0 mm+ – industrial or mechanical strength

Thicker walls offer greater load capacity and impact resistance.

Choosing the Right Size

Select your tubing based on:

• Weight or load requirements
• Whether the tube must support bending or twisting
• Where it will be installed (indoor/outdoor)
• How it will be joined (welded/bolted/slotted)
• Aesthetic preferences for visible structures

If unsure, always choose a slightly thicker tube for safety.

How to Choose the Right Round Steel Tubing

When selecting round steel tubing, consider the following:

• Load requirements – thicker walls for heavy-duty jobs
• Indoor vs outdoor use – galvanised or stainless for outdoor areas
• Welding needs – mild steel is easiest to weld
• Appearance – round tubes are ideal for visible structures
• Budget – mild steel is most cost-effective
• Engineering standards – ensure the tubing meets AS/NZS or ASTM requirements

Choosing the correct size and material ensures durability, safety, and long-term performance.

Round Steel Tubing Supplier in Perth – Lintel Steel

At Lintel Steel, we supply a wide range of round steel tubing for builders, welders, DIY users, and fabrication workshops across Perth. With more than 11 years of industry experience, we provide high-quality steel tubing cut to your required length with fast turnaround.

We offer:

• Mild steel round tubing
• Galvanised round tubing
• Large and small diameters
• Custom cutting and processing
• Fast delivery across Perth
• Free quotes within 48 hours

Whether you’re building handrails, gates, machinery frames, or structural supports, Lintel Steel has the right tubing for your project.

Conclusion

Round steel tubing is a strong, versatile, and easy-to-use material for construction, fabrication, and engineering work. With a wide range of sizes, materials, and thicknesses available, it can be used in everything from residential gates to industrial machinery. Choosing the right tubing ensures your structure stays strong, safe, and long-lasting.

For dependable round tubing supply in Perth, contact Lintel Steel today.

Click here to get a quote and quantity takeoff for free.

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