Outdoor furniture needs to do much more than look good. It must withstand changing weather conditions, regular use and years of exposure to moisture, temperature fluctuations and UV rays. Whether you're building a garden bench, picnic table, outdoor dining set, pergola or bespoke seating area, selecting the right steel section is one of the most important decisions you'll make.
Different steel profiles offer different levels of strength, weight, appearance and ease of fabrication. Choosing the correct section from the start will help create furniture that is durable, safe and visually appealing, while also making the fabrication process more straightforward.
In this guide, we'll look at the most commonly used steel sections for outdoor furniture and explain where each one performs best.
Why Steel Is an Excellent Choice for Outdoor Furniture
Steel has become one of the most popular materials for modern outdoor furniture because it combines strength, longevity and design flexibility. Unlike timber, steel will not warp, split or become damaged by insects, while offering far greater structural strength than many alternative materials.
Steel also works exceptionally well alongside other materials. Timber slats, composite decking boards, glass and stone can all be incorporated into steel-framed furniture to create contemporary designs suitable for gardens, patios, restaurants, parks and commercial spaces.
When properly protected through galvanising or powder coating, steel furniture can provide decades of reliable service with relatively little maintenance.
Square Hollow Section for Modern Furniture Frames
Square Hollow Section (SHS), often referred to as steel box section, is one of the most versatile materials for outdoor furniture fabrication. Its clean, symmetrical appearance makes it particularly popular for modern garden furniture where straight lines and minimalist styling are preferred.
Because strength is distributed evenly across all four sides, SHS provides excellent rigidity while maintaining a neat appearance. It is ideal for chair legs, bench frames, dining tables, planter frames and outdoor storage units.
Smaller sections can be used for lightweight furniture, while larger wall thicknesses provide additional strength for heavy-duty commercial installations such as public seating or picnic tables.
At DC Iron, our range of Steel Box Section is suitable for everything from small decorative furniture projects to large structural fabrications.
Rectangular Hollow Section for Larger Tables and Benches
Rectangular Hollow Section (RHS) is often chosen where longer spans need additional strength without adding unnecessary weight.
Its wider profile provides increased stiffness in one direction, making it particularly suitable for table frames, bench supports and larger outdoor structures. Many fabricators choose RHS for dining tables because it allows long tabletops to remain stable while keeping the frame visually slim.
It also lends itself well to contemporary furniture designs where horizontal lines are a key design feature.
Round Steel Tube for Softer, Contemporary Designs
While square and rectangular sections dominate modern furniture design, round steel tube remains an excellent choice where softer aesthetics are required.
Curved frames, café furniture, stools, handrails and decorative garden seating often benefit from the smooth appearance of circular tube. It also works particularly well when bending or rolling sections to create bespoke shapes.
Round tube offers excellent strength while producing furniture with a lighter visual appearance than box section.
It is also commonly used alongside key clamp fittings to create modular outdoor furniture that can be assembled without welding.
Flat Bar for Support and Decorative Features
Flat bar is frequently overlooked, yet it plays an important role in outdoor furniture fabrication.
It is commonly used for support rails beneath seating, cross bracing, decorative edging, armrests and mounting points. Flat bar can also be combined with timber or composite boards to create attractive slatted furniture designs.
Because it is available in various widths and thicknesses, it offers considerable flexibility while remaining easy to cut, drill and weld.
Choosing the Right Wall Thickness
Selecting the correct wall thickness is just as important as choosing the section itself.
Using material that is too light can lead to excessive flexing, particularly on longer benches or tables. On the other hand, unnecessarily thick sections increase both weight and cost without always providing meaningful benefits.
For most domestic outdoor furniture, moderate wall thicknesses provide an excellent balance between strength and ease of fabrication. Heavier commercial installations, public seating or furniture expected to experience high levels of use may benefit from thicker sections for additional durability.
The intended application should always determine the specification rather than simply selecting the heaviest steel available.
Don't Forget Corrosion Protection
Even the strongest steel section will eventually deteriorate if it is left unprotected outdoors.
Galvanising provides excellent long-term corrosion resistance, particularly for furniture exposed to the British weather throughout the year. Powder coating offers additional protection while allowing furniture to be finished in a wide range of colours, making it particularly popular for residential gardens and commercial outdoor spaces.
Design also plays an important role. Avoiding water traps, allowing adequate drainage and sealing exposed ends with suitable caps all help extend the life of outdoor furniture.
Think About Fabrication Before Ordering Materials
The best steel section is not always the strongest. It is the one that suits both the finished furniture and the fabrication process.
Consider how components will be cut, welded, drilled and transported before deciding on the final material. Larger sections may provide additional strength but can make fabrication slower and increase material costs. Smaller sections often produce cleaner, more elegant furniture while remaining perfectly adequate for the intended load.
Planning these details early helps avoid unnecessary waste and produces a better finished product.
Building Outdoor Furniture That Lasts
Outdoor furniture represents a long-term investment, whether it is being built for a private garden, hospitality venue or public space. Choosing the right steel sections ensures that the finished product remains strong, stable and attractive for many years.
Square Hollow Section provides outstanding versatility for most furniture frames, Rectangular Hollow Section is ideal for longer spans, round tube creates softer contemporary designs and flat bar offers valuable structural and decorative support. Combined with appropriate corrosion protection and quality fabrication, these materials form the foundation of durable outdoor furniture that performs in all seasons.
Find Quality Steel Sections at DC Iron
At DC Iron, we supply a comprehensive range of stainless steel components, such as steel box section, rectangular hollow section, round tube and flat bar for projects of every size. Whether you're manufacturing bespoke garden furniture, commercial seating or architectural outdoor features, our high-quality steel products provide the strength, consistency and reliability needed to achieve professional results.