Aluminium tube and box section: alloys, sizes and uses

Aluminium tube is a light, corrosion-resistant hollow section used for frames, handrails, structures and furniture, in round, square and rectangular forms. ULAMEX supplies aluminium tube and box section in EN AW-6060, 6063 and 6082, in standard 3,000 and 6,000 mm lengths, to EN 755. This guide covers the section types, the alloys, sizes and finishes, structural use and fabrication.

What aluminium tube is

Aluminium tube is an extruded hollow section: round tube, square tube and rectangular tube, the square and rectangular forms often called box section. Being hollow, it resists bending and torsion efficiently for its weight, which is why it makes strong, light frames and structures. A tube is described by its outside dimensions and wall thickness, for example a 40 x 40 mm square tube with a 2 mm wall. All tube is supplied to EN 755 (extruded products) in alloys designated under EN 573-3.

Section types

Round tube is the choice for handrails and anything turned or bent; square and rectangular box section make efficient columns, posts and frame members and are easy to connect flat to flat.

Alloys for aluminium tube

The alloy is matched to the duty, exactly as for solid profiles. EN AW-6060 and 6063 give the fine surface and clean anodising used for architectural and general tube; EN AW-6082 gives the higher strength needed for load-bearing frames.

For the full alloy detail see our guide to EN AW aluminium alloys, and for the solid and open profiles see aluminium profiles.

Sizes, lengths and tolerances

ULAMEX stocks tube in standard lengths of 3,000 and 6,000 mm. A tube is specified by its outside dimensions and wall thickness, quoted with mass per metre. Two tolerance standards apply: general extruded tube is supplied to EN 755-9, and precision tube in 6060 and 6063, held to closer tolerances, to EN 12020-2. State the alloy, temper, section, dimensions, length and finish with an enquiry for an accurate quotation.

Structural use of box section

Square and rectangular box section is the efficient choice for aluminium frames because a closed section resists bending and torsion well for its weight. Where a member carries load, it is designed to Eurocode 9 (EN 1999) in 6082-T6, with deflection checked as well as strength, since aluminium deflects more than steel for the same section. Carports, canopies, walkways and machine frames use box section for this reason, often alongside solid profiles on the same structure.

Finishes

Aluminium tube is supplied as mill finish or powder coated. Powder coating gives any RAL colour for a durable, even finish, and ULAMEX confirms the RAL colour on the order line, so tube, profiles and fittings on a job read as one system. Aluminium also anodises well, with 6063 giving the brightest finish, which ULAMEX can advise on where anodising through a specialist is the better route.

Corrosion resistance and outdoor life

Aluminium tube forms a natural oxide layer that protects it in most atmospheres, which is why it is used outdoors without a coating and never rusts. For coastal and industrial exposure an anodised finish builds a thicker, harder oxide that extends the life further, and a powder-coated finish adds both colour and protection. Unlike steel, an aluminium tube does not need galvanising or repainting to survive outdoors, which is a large part of why it is chosen for handrails, carports and facade frames that must stay maintenance-free for decades.

Applications

Aluminium tube serves a wide range of work. Handrails and balustrades use round tube in an anodised or powder-coated finish. Furniture, displays and shopfitting use light tube for its surface and low weight. Carports, canopies and pergolas use box section frames. Transport and trailer building uses tube where every kilogram saved adds payload. Machine guarding, frames and light structures use square and rectangular tube for easy connection. In each case the same stock alloys and finishes apply.

Aluminium tube for handrails and balustrades

Round aluminium tube in 6063 is a common choice for handrails and balustrades, light to handle and clean to anodise or powder coat. The tube pairs with aluminium or stainless fittings, brackets, posts and glass clamps to build a complete system, and the low weight makes long runs easy to install. For a coastal balustrade the tube is anodised or coated for the exposure. The same tube serves balcony, terrace and stair railings in residential and commercial work.

Fabricating aluminium tube

Aluminium tube is bent on a mandrel bender to keep its section through the bend. It welds by TIG and MIG with a 4043 or 5356 filler, losing some strength in the heat-affected zone, which the designer allows for; box section is also bolted or joined with connectors for frames. Tube machines, drills and notches readily, so material arrives ready to fabricate. For the filler detail by alloy, see the EN AW aluminium alloys guide.

Weight of aluminium tube

Aluminium has a density of about 2.70 g/cm3, so tube is light to handle and cheap to transport. The mass of a tube is its cross-sectional area times the density, quoted per metre; a square tube of 40 x 40 mm with a 2 mm wall weighs roughly 0.82 kg per metre. Mass per metre is the figure to compare between sections, and it is given on the profile data for each stocked tube.

Aluminium tube versus steel tube

Aluminium tube is about one third the weight of steel tube, does not rust and needs no coating for corrosion resistance, which makes it the choice for handrails, frames, transport and outdoor structures where weight and corrosion matter. Steel tube is stronger and stiffer for the same section and cheaper per kilogram, so it wins where strength or budget dominates. ULAMEX supplies both, so a project can compare and source the right tube from one supplier.

Standard and custom sections

Alongside standard round, square and rectangular tube, custom hollow sections are available on a project basis where a job needs a section that is not a stock size. Send the drawing or the section requirement with your quote request and the technical desk will confirm feasibility, alloy, temper, finish and lead time. For stock tube no minimum order applies and mixed pallets are standard.

Aluminium tube from ULAMEX

ULAMEX has supplied the aluminium trade since 1988, and tube and box section are a core part of the range.

Need aluminium tube or box section for a project? Send the section, alloy, temper, dimensions, length and finish, and ULAMEX will return a non-binding quotation. Browse the aluminium tube and rod range, see our aluminium sheet guide and supply capabilities, or contact the export desk at [email protected] or +48 504 424 761.

Frequently asked questions