Aluminium profiles: types, alloys, sizes and finishes

Aluminium profiles are extruded sections used as the structural and architectural building blocks of fabrication. ULAMEX supplies the full range of standard profiles, angle, channel, T-slot, flat bar, T-bar, gate profiles and tube, in the EN AW-6060, 6063 and 6082 alloys, in standard 3,000 and 6,000 mm lengths. This guide covers the profile types, the alloy and temper to specify, sizes and tolerances, finishes, and how to order.

What aluminium profiles are

An aluminium profile is a section formed by extrusion: a heated aluminium billet is pushed through a shaped die under pressure, producing a continuous length with a fixed cross-section. The extrudate is then stretched, cut to length, and heat treated to the required temper. The terms “aluminium profile” and “aluminium extrusion” describe the same product, the profile being the section and the extrusion being the process that makes it.

Extrusion is what makes aluminium so versatile for fabrication: a single die can produce a complex, application-specific cross-section in long, light, corrosion-resistant lengths. ULAMEX stocks the standard profiles that cover most industrial and construction work, and supplies custom cross-sections on a project basis. All profiles are manufactured to EN 755 (extruded products) in alloys designated under EN 573-3.

How aluminium profiles are made

Extrusion turns a solid billet into a finished profile in a few controlled stages, and understanding them helps when you specify a section.

The aluminium billet is heated to around 450 to 500 degrees C, soft but not molten, then forced by a hydraulic ram through a hardened steel die that carries the negative of the cross-section. The emerging profile is cooled, then stretched to straighten it and relieve internal stress. Lengths are sawn, and 6xxx profiles are artificially aged in an ageing oven to reach the T5, T6 or T66 temper. Finally the profile is finished: left as mill finish, anodised, or powder coated.

Two points follow for the buyer. First, the temper is set after extrusion, so the same alloy can be supplied at different strengths (T5, T6, T66). Second, a custom section needs a custom die, which is why bespoke profiles are quoted per project while standard profiles ship from stock.

Standard aluminium profile types

The profiles below are the workhorses of fencing, carports, PV mounting, machine building and architectural work. ULAMEX holds them in stock alongside aluminium pipes and rods and aluminium sheet.

Round, square and rectangular tube and the solid bar sections (smooth round bar, flat bar, T-bar) sit in the pipes and rods range; the open profiles (angle, channel, T-slot, gate) sit in the profiles and sections range. Both travel on one order.

T-slot and modular framing profiles

T-slot profiles are extruded sections with one or more longitudinal slots that accept sliding nuts and connectors, so frames bolt together without welding. They are the basis of machine framing, safety guarding, workstations, jigs and test rigs, where a structure has to be built, adjusted and rebuilt quickly.

T-slot systems come in a range of profile sizes and slot series, specified by the cross-section and the slot width. The matching connectors, brackets, sliding nuts and end caps let a fabricator assemble a rigid frame with hand tools alone. EN AW-6063 is the usual alloy, for its clean extruded surface and consistent slot dimensions. Tell ULAMEX the profile size and slot series you work with and the team will confirm availability and quote the sections and connectors you need.

Choosing between angle, channel, tube and flat bar

The section shape decides how a profile carries load and how it is fixed.

Angle (L) is the general-purpose section for frames, edging and brackets, fixed on two faces. Channel (U) encloses an edge or carries a panel and gives more stiffness than an angle of the same weight. Tube (round, square or rectangular) is the strongest section for its weight in bending and torsion, which makes it the choice for carport frames, structures and handrails. Flat bar is the simplest solid section, for bracing, supports and machined parts. T-bar suits frames and joints where two members meet at a face.

For a load-bearing member, section and alloy work together: a square tube in 6082-T6 carries far more than the same tube in soft 6060. Where the duty is structural, send the load case with your enquiry and ULAMEX will confirm the section and temper.

Which alloy and temper to specify

Profile performance depends on the alloy and temper as much as the shape. The three 6xxx (AlMgSi) alloys cover almost all profile work, and the choice follows the duty: surface and extrudability for architectural sections, strength for load-bearing members.

The T66 temper guarantees higher proof and tensile strength than standard T6 on the same alloy, which is why PV mounting and architectural specifications often call for 6060-T66 or 6063-T66. For the full alloy properties, composition and selection logic, see our guide to EN AW aluminium alloys.

Standard sizes, lengths and tolerances

ULAMEX stocks profiles in standard lengths of 3,000 and 6,000 mm, with no minimum order quantity on stocked SKUs, so you order the lengths a job needs rather than a forced pallet.

Two tolerance standards apply. Extruded profiles for general applications are supplied to EN 755-9. Precision profiles in 6060 and 6063, held to closer tolerances on dimensions and form, are covered by EN 12020-2. Where an architect or main contractor asks for the section tolerances on paper, ULAMEX supplies the relevant EN 755 or EN 12020 tolerance data on request, traceable to the delivered section.

Structural design with aluminium profiles

Where an aluminium profile carries structural load, it is designed to Eurocode 9 (EN 1999), the standard for aluminium structures, just as steelwork is designed to EN 1993. The Eurocode accounts for the lower stiffness of aluminium, whose elastic modulus is about one third that of steel, the strength of the alloy and temper, and the reduction in strength in the heat-affected zone of a weld. For a carport, canopy or frame the designer chooses 6082-T6 for its strength and checks deflection as well as strength, because aluminium deflects more than steel for the same section. ULAMEX supplies profiles to EN 755 with the alloy, temper and tolerance documentation a structural check needs.

How to specify an aluminium profile

A complete profile specification has five parts, and giving all five with a quote request gets you an accurate price and lead time first time.

Profiles are described by their cross-section dimensions and wall thickness, with mass quoted per metre. If you are not sure of the exact section, send a drawing or a sample and ULAMEX will identify the nearest stock profile or quote a custom one. Where a section is not held in stock, the team confirms availability rather than guessing.

Weight of aluminium profiles

Aluminium has a density of about 2.70 g/cm3, roughly one third that of steel, which is the main reason profiles are chosen where handling and transport weight matter. The mass of a profile is its cross-sectional area times the density, quoted per metre, so a section of 10 cm2 weighs about 2.7 kg per metre. Mass per metre is the figure to compare when weighing one section against another, and it is given on the profile data for each stocked section.

Finishes: mill, anodised and powder coated

Aluminium profiles take three finish routes. Mill finish is the as-extruded surface, suitable where appearance is secondary or a coating follows. Anodising builds a hard, corrosion-resistant oxide layer and is the architectural standard; EN AW-6063 gives the cleanest, brightest anodised finish, with 6060 close behind. ULAMEX supplies profiles in mill finish and powder coated to order, and can advise where anodising through a specialist is the better route.

Powder coating gives any RAL colour with a durable, even finish. ULAMEX confirms the RAL colour on the order line and the dispatch note, so a fence, gate and matching posts read as one system across a job. Common architectural colours include RAL 9005 (jet black), RAL 7016 (anthracite grey), RAL 9016 (traffic white) and RAL 6005 (moss green).

Finish standards and durability

Where a finish has to meet a specification, two quality standards apply to aluminium profiles. Architectural anodising is usually specified at a coating thickness of 15 to 25 microns, with the Qualanod label setting the process requirements. Powder coating quality is defined by the Qualicoat standard, which covers adhesion, cure and weathering. Specify the Qualicoat powder-coat grade when the project demands it, and confirm it on the order line.

Both routes extend outdoor life well beyond mill finish. Anodising builds an integral oxide layer that will not flake or peel, while powder coating gives a tough, even colour film. For coastal and industrial atmospheres the finish works together with the alloy choice: a 6xxx profile, anodised or powder coated, handles most exterior architectural and fencing exposure for decades.

Joining and fabricating aluminium profiles

Aluminium profiles are joined by welding, bolting or modular connectors, depending on the section and the job.

The 6xxx profiles are weldable by TIG and MIG, usually with 4043 or 5356 filler; the joint loses some strength in the heat-affected zone, which the designer allows for. Bolted and riveted joints avoid that softening and suit field assembly. T-slot profiles use sliding nuts and connectors for a bolt-together frame with no welding at all. Profiles also machine cleanly, so drilling, tapping, mitring and notching are straightforward in the workshop.

ULAMEX supplies profiles in standard stock lengths, so the fabricator receives material ready to assemble. For the filler alloy and weldability detail by grade, see the guide to EN AW aluminium alloys.

Aluminium profiles by sector

The same profile families serve several sectors, with the alloy and finish changing to suit the job.

Fencing, gates and carports. Slat louvres, fence profiles, gate sections and posts are built in 6060 and 6063 for the fine sections and clean RAL finish, while load-bearing carport and pergola frames step up to 6082-T6. This pairing runs through the ULAMEX modern fencing system and profile ranges.

PV mounting. Solar mounting rails use 6060 and 6063 in T6 or T66: light to handle on a roof, strong enough for standard panel spans, and corrosion resistant for a long outdoor life. ULAMEX supplies these alongside stainless fasteners as part of its PV mounting components range.

Machine building and architecture. T-slot profiles in 6063 frame machines, jigs, guarding and workstations, while structural members and walkways use 6082-T6. Window frames, trim and decorative sections favour 6063 for the anodised finish.

Thermal break profiles

Aluminium conducts heat well, which is a drawback in windows, doors and facades where a solid profile would bridge heat between inside and outside. Thermal break profiles address this by joining an inner and an outer aluminium section with an insulating polyamide strip, so the metal path is interrupted and the assembly meets the thermal performance a building envelope requires. This is why architectural glazing and curtain walling use thermal-break systems rather than solid profiles. For a project that needs thermal-break or architectural sections, send the requirement with your quote request and the technical desk will confirm what can be supplied.

Further applications of aluminium profiles

Beyond fencing, PV and machine building, aluminium profiles serve a wide range of work where light weight, corrosion resistance and a clean finish matter.

Balustrades and handrails use tube and channel in 6063 for the anodised finish. Facades and cladding rely on extruded carrier and trim profiles. Transport and trailer building uses profiles and tread plate where every kilogram saved adds payload. Displays, signage and furniture favour slim 6063 sections for their surface quality. In each case the same stock alloys (6060, 6063, 6082) and finishes apply, so a fabricator can move between sectors with one supplier.

Aluminium profiles versus steel sections

Aluminium is roughly one third the weight of steel, which is the main reason fabricators choose aluminium profiles for fencing, carports, facades and solar structures: lighter to handle, lighter to transport and easier to install, with natural corrosion resistance that needs no galvanising. Steel still wins where maximum strength or stiffness per cross-section is the priority, or where cost per tonne dominates.

Because ULAMEX supplies both, a project that mixes aluminium profiles with structural or stainless steel can be sourced on one order, one delivery and one invoice. Where aluminium and steel are fixed together, use compatible stainless fasteners and isolate dissimilar metals in wet conditions to avoid galvanic corrosion.

Recyclability and lifecycle

Aluminium is fully and repeatedly recyclable: remelting scrap uses around 5 percent of the energy needed to produce primary metal, and a recycled profile performs identically to the original. For specifiers working to sustainability criteria, this gives aluminium profiles a low lifecycle footprint, especially where recycled content is available. Combined with a service life measured in decades, the recyclability makes aluminium a long-term economic as well as structural choice.

Custom and bespoke profiles

Alongside the standard range, ULAMEX supplies custom cross-sections on a project basis. Where a job needs a section that is not a stock profile, 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 profiles, no minimum order quantity applies and mixed pallets are standard, so a fabrication job can take a few lengths of several profiles on one delivery.

Why source aluminium profiles from ULAMEX

ULAMEX has been active in the metal wholesale trade since 1988, supplying steel and aluminium to professional buyers across continental Europe. Aluminium is a priority sector, and profiles are a core part of the range.

Need aluminium profiles for a project? Send your profile type, alloy, temper, finish and length, and ULAMEX will return a non-binding quotation with current availability, lead time and pricing. Browse the full aluminium profiles and sections range, or contact the export desk at [email protected] or +48 504 424 761. For our full range, certification and quote process, see steel and aluminium supply capabilities.

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