A wide flange beam, often known as an H-beam, is one of the most important structural steel sections used in construction. With its wide, parallel flanges and strong web, a wide flange beam provides excellent load-bearing strength and stability, making it ideal for building frames, floors, roofs, bridges, and industrial structures. Its shape allows it to carry heavy loads over long spans while keeping weight and material use efficient.

Whether you are a builder, steel fabricator, engineer, or DIY user working on a structural project, understanding how wide flange beams work can help you choose the right size and type for your design. In this guide, we explain what wide flange beams are, why they are used, common sizes, and how they compare to other beam types.

What Is a Wide Flange Beam?

A wide flange beam, often referred to as a W-beam, is a structural steel section with a wide, parallel flange and a central web. Unlike traditional I-beams with tapered flanges, wide flange beams have flat, evenly sized flanges, giving them superior bending strength, stability, and load-carrying performance.

They are commonly used in commercial buildings, industrial structures, bridges, mezzanines, and heavy framing because they can support significant vertical and horizontal loads without twisting or buckling.

Key Features and Advantages of Wide Flange Beams

Wide flange beams are popular in structural design because of their engineering benefits:

1. High Strength-to-Weight Ratio

The wide flanges distribute weight efficiently, allowing the beam to carry heavier loads while keeping overall weight manageable.

2. Excellent Bending Resistance

Their deep web and broad flanges give wide flange beams strong resistance against bending and deflection across long spans.

3. Greater Stability

Parallel flanges improve lateral stability and reduce the risk of twisting, making them ideal for floors, roofs, and column supports.

4. Easy to Weld, Bolt, and Connect

The flat flange surfaces simplify fabrication, installation, and connection to other steel sections.

5. Available in Many Sizes

Wide flange beams come in multiple depths, flange widths, and thicknesses, allowing engineers to match the exact strength requirements of each project.

6. Suitable for Heavy Structural Loads

They are often used in large commercial buildings, warehouses, and industrial plants where strength and rigidity are critical.

Common Applications of Wide Flange Beams

Because of their strength and versatility, wide flange beams are used in:

• Building frames (columns, beams, lintels)
• Warehouses and factories
• Mezzanine floors and platforms
• Bridges and overpasses
• Mining and industrial structures
• High-rise building frameworks
• Equipment and machinery supports
• Structural retrofitting and reinforcement

Their ability to support heavy loads makes them essential in almost every major structural project.

Wide Flange Beam Sizes and Specifications

Selecting the correct wide flange beam size is essential for achieving the strength, stiffness, and safety needed in any structural design. Wide flange beams are produced in a variety of depths, flange widths, and thicknesses so engineers can match the beam precisely to the loading and span requirements of a project.

How Wide Flange Beam Sizes Are Classified

Wide flange beams are typically designated by:

W (beam type) + depth (mm) × weight per metre (kg/m)

For example:

• W200×22 → 200 mm depth, 22 kg per metre
• W250×33 → 250 mm depth, 33 kg per metre
• W310×39 → 310 mm depth, 39 kg per metre
• W360×51 → 360 mm depth, 51 kg per metre

This naming system helps engineers quickly understand the structural capacity, stiffness, and expected performance of each beam.

Typical Size Range for Wide Flange Beams

Although manufacturers offer many variations, common ranges include:

• Depth: 150 mm – 610+ mm
• Flange width: 100 mm – 250 mm
• Web thickness: 5 mm – 20 mm
• Flange thickness: 8 mm – 35 mm
• Weight per metre: 14 kg/m – 200+ kg/m

Larger beams (e.g., 460–610 mm deep) are often used in commercial, industrial, and long-span designs where bending strength and stiffness are critical.

Key Specifications Engineers Analyse

Choosing the correct wide flange beam involves evaluating several structural properties:

1. Section Modulus (Sx)

Indicates bending capacity. A higher Sx means the beam can resist more bending without failing.

2. Moment of Inertia (Ix)

Measures stiffness. A higher Ix reduces deflection over long spans.

3. Web Thickness & Flange Thickness

• Thicker webs resist shear forces.
• Thicker flanges prevent local buckling and improve stability.

4. Flange Width

Wider flanges improve lateral stability and reduce the risk of twisting (lateral–torsional buckling).

5. Weight Per Metre (kg/m)

Heavier beams are stronger but also cost more.
Engineers select the most efficient size to balance performance and cost.

Engineering Factors That Determine Beam Size

A wide flange beam is never chosen by guesswork — each size must match the structural demand. Engineers consider:

Span Length

Longer spans require deeper beams to control bending and avoid excessive deflection.

Dead Load & Live Load

Dead load = weight of building materials

Live load = people, equipment, furniture, machinery

Heavier loads demand thicker, stronger beam sections.

Wind Loads and Seismic Loads

Important for tall buildings, roof structures, and industrial facilities.

Support Spacing

Closer support spacing allows smaller beam sizes; wider spacing requires deeper beams.

Deflection Limits

Too much deflection causes cracking of walls or uneven floors. Building codes set maximum allowable deflections to ensure comfort and safety.

Building Standards (AS/NZS, ASTM, EN)

Wide flange beams must comply with design codes for material properties, geometry, and strength.

Why Size Matters in Real-World Projects

Using an undersized beam can cause:

• Sagging floors
• Cracks in walls
• Structural vibration
• Excessive deflection under load
• Risk of beam failure

Using an oversized beam can cause:

• Higher material cost
• Increased handling and installation effort
• Unnecessary weight added to the structure

The best beam is one that meets strength needs efficiently and safely.

Common Wide Flange Beam Sizes Used in Australia

Some widely used W-beam sizes include:

• W200×15, W200×22, W200×31
• W250×25, W250×33, W250×44
• W310×23, W310×32, W310×39, W310×51
• W360×39, W360×51, W360×64
• W460×89, W460×113
• W530×92, W530×109
• W610×125, W610×140, W610×174

These cover most residential, commercial, and industrial structural needs.

Wide Flange Beam vs. I-Beam: What’s the Difference?

While both beams serve similar purposes, wide flange beams offer key advantages:

• Parallel flanges = easier connections
• Broader flange width = better stability
• Optimised shape = higher load capacity
• More uniform strength = suitable for long spans

Wide flange beams are considered the modern evolution of traditional I-beams, offering improved performance in nearly every structural application.

How to Choose the Right Wide Flange Beam

Selecting the correct beam depends on several factors:

1. Structural Load Requirements

Heavier beams are required for high-load areas like floor beams or long-span roofs.

2. Span Length

Longer spans require deeper beams to control bending and deflection.

3. Connection and Fabrication

Welding, bolting, and bracing requirements influence flange thickness and connection plate selection.

4. Environmental Conditions

Outdoor or coastal builds may need galvanised or coated beams to prevent corrosion.

5. Engineering Approval

All wide flange beams used in structural frames must meet engineering design criteria and relevant building standards.

Wide Flange Beam Supplier in Perth – Lintel Steel

At Lintel Steel, we supply a full range of wide flange beams for residential, commercial, and industrial projects across Perth. With over 11 years of experience, we provide steel beams that meet Australian Standards and suit both small builds and large structural jobs.

We offer:

• Wide flange beams in common and custom sizes
• Cut-to-length service
• Welding, drilling, and basic fabrication
• Fast delivery across Perth
• Friendly technical support
• Free quotes within 48 hours

Whether you’re building a house, warehouse, mezzanine, or industrial platform, Lintel Steel ensures you get strong, reliable beams for long-lasting performance.

Conclusion

A wide flange beam is one of the strongest and most efficient structural steel sections available today. Its wide flanges, deep web, and stable design make it ideal for supporting heavy loads in both simple and complex building projects. Choosing the right size ensures safety, stability, and long-term strength in any structure.

For dependable wide flange beam supply in Perth, contact Lintel Steel for expert advice and fast service.

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

You can find out more about us at our Fanpage Lintel Steel.