An aluminium door profile is an extruded section, almost always in 6060 or 6063 alloy, that forms the frame, sash, mullion, threshold or track of a door. Getting the profile right means choosing the alloy and temper, the wall thickness and section depth for the door size, a thermal break where energy rules demand it, and a finish class matched to the climate. This guide explains each decision for fabricators, system houses and project buyers who purchase the aluminium.
A door is the most heavily used moving part of a building envelope. A residential entrance door may open and close tens of thousands of times over its life; a shopfront door in a busy street can see that many cycles in a single year. The aluminium profiles that make up the frame and leaf carry the glass and infill, hold the hinges, locks and rollers, resist wind pressure, keep out air and rain, and in most climates now also limit heat loss.
Aluminium suits this job because it can be extruded into almost any cross-section. A single die can produce a profile that combines a glazing pocket, gasket grooves, a drainage chamber, a screw port for corner cleats, a channel for the lock body and a decorative face, all in one piece with consistent dimensions along a 6 m length. Timber and steel cannot integrate so many functions without machining or assembly, and uPVC needs steel reinforcement in large sizes.
Metline supplies the aluminium itself: extruded door profiles in mill finish, anodised or coated condition, thermal-break profiles, flat bar, sheet and coil for infill panels, and related sections to customer or system-house drawings. We do not fabricate, assemble or install finished doors. The rest of this guide therefore looks at the door from the point of view of the profile buyer: what the finished door must achieve, and what that means for the extrusion you order.
Every door system, whatever its opening style, is built from a family of extrusions designed to work together. A typical system catalogue lists 20 to 60 profiles, but they fall into a small number of functional groups:
| Profile | Function | What to check when ordering |
|---|---|---|
| Outer frame (jamb and head) | Fixed perimeter fixed to the wall opening; carries hinges or tracks | Wall thickness at fixing points, screw-port position, tolerance on overall depth |
| Sash or leaf profile | Moving frame that holds the glass or infill panel | Inertia (Ix, Iy) for the leaf height, glazing pocket width |
| Mullion and transom | Divide the frame into panels; carry wind load between fixings | Moment of inertia and section modulus; often the deepest profile in the system |
| Threshold (sill) | Bottom member at floor level; sheds water and forms a seal | Height for accessibility rules, drainage slots, wear resistance of the top face |
| Track and rail profiles | Guide rollers on sliding and folding doors | Hardness and straightness of the running surface; often thicker walls |
| Interlock and meeting stile | Where two sliding leaves overlap or two hinged leaves meet | Gasket groove geometry and straightness over full length |
| Glazing bead | Clips in to retain the glass | Clip fit tolerance; usually a precision profile of thin wall |
| Cover caps and adaptors | Hide fixings, extend frames, couple units | Surface finish quality on visible faces |
| Corner cleats | Inserted into profile chambers to join mitred corners | Often cut from extruded bar or special cleat profiles; tight fit tolerance |
Glazing beads, interlocks and cover caps are dimensionally the most sensitive parts because they rely on clip or snap fits measured in tenths of a millimetre. Frames, mullions and tracks are the structurally critical parts. Many fabricators therefore order precision tolerances for the clip-fit profiles and standard tolerances for the rest, which keeps die and inspection costs reasonable.
The opening system changes what the profiles must do. A sliding door profile is designed around its track; a hinged door profile around its hinge loads and corner strength. The cards below summarise the engineering priorities for each type.
Leaves run on rollers in a bottom track. The track profile needs a straight, hard-wearing running surface, and the leaf profile must be stiff enough not to bow between rollers. Interlocks need tight tolerances to seal. Two-, three- and multi-track systems are common for balconies and patios.
Large leaves (often 200 to 400 kg each) are lifted off their seals by the handle before sliding. Profiles are deep, with heavy walls in the bottom rail and a reinforced track; 6063-T6 or 6005A-T6 is often chosen for the highest leaves.
Leaves hinge together and fold to one side on top-hung or bottom-running gear. Hinge zones see concentrated loads, so the leaf profile needs thick walls where hinges screw in and close straightness tolerances so the folded stack aligns.
Single or double leaves on butt, pivot or concealed hinges. The hinge-side stile carries the whole leaf weight as a cantilever, and the corners must resist racking. Corner cleats and crimping or pinning give the strength, so cleat chambers must be dimensionally accurate.
Large leaves rotate on floor and head pivots set in from the edge. The stile and rails must be very stiff, and the bottom rail often carries the pivot load directly. Deep sections with internal webs are typical.
The leaf slides into a wall cavity on a top track. The top-hung track profile carries the full leaf weight and must be straight over long spans. Leaf profiles are usually slim because there is no weather exposure.
Visible frame widths of about 20 to 40 mm maximise glass area. Strength comes from section depth rather than width, and the glass often contributes stiffness. Profiles need excellent surface quality and very tight tolerances.
No weather loads, so walls can be thinner and thermal breaks are unnecessary. Appearance, straightness and accurate clip fits for panels and glass matter most. 6063-T5 with anodised or powder finish is standard.
High traffic, door closers and panic hardware put heavy cyclic loads on corners and stiles. Wide stiles with thick walls (often 2.5 to 3 mm or more at hardware zones) and reinforced corners are normal.
For deeper reading on complete systems, see our pages on sliding door systems, bifold doors, hinged door systems and slimline doors, all written for profile buyers.
Almost all architectural door profiles are made from the 6xxx (Al-Mg-Si) family because these alloys extrude easily into thin, complex sections, harden by heat treatment and anodise well. The choice between them is a balance of surface quality, strength and extrusion speed.
| Alloy | Typical tempers | Strengths | Typical use in doors |
|---|---|---|---|
| 6063 (EN AW-6063) | T5, T6, T66 | Excellent surface, very good anodising response, good corrosion resistance, extrudes complex hollow sections at high speed | The global default for frames, leaves, beads and tracks |
| 6060 (EN AW-6060) | T5, T6, T66 | Slightly leaner than 6063, so even better surface and extrusion speed; marginally lower strength | The standard window and door alloy in much of Europe |
| 6005A (EN AW-6005A) | T6 | Higher strength than 6063 with reasonable surface quality | Heavy lift-and-slide rails, pivot door stiles, large mullions |
| 6061 (EN AW-6061) | T6 | High strength, good machinability; poorer extrudability and anodised appearance than 6063 | Occasional structural inserts and heavy sections, rarely visible members |
| 6082 (EN AW-6082) | T6 | Highest strength of the common 6xxx alloys | Structural reinforcement in very large doors; seldom used for visible profiles |
Old marketing material sometimes calls 6061 the "most popular" door alloy. In practice it is not: 6061 extrudes more slowly, is harder to push through the thin, multi-chamber dies used for doors, and gives a less uniform anodised colour. It earns its place only where a member needs extra strength and the appearance or cost penalty is acceptable.
Temper matters as much as alloy. T5 means the profile is cooled directly from the press and then artificially aged. T6 means it is fully solution heat-treated and quenched (in practice, press quenching with water or forced air) before ageing, giving higher strength. T66 is a European designation for 6060 and 6063 processed to a higher strength level than standard T6 through tighter control of composition and quenching.
| Alloy and temper | Minimum tensile strength Rm | Minimum 0.2 % proof strength Rp0.2 | Wall thickness range |
|---|---|---|---|
| 6060-T5 | 160 MPa | 120 MPa | up to 5 mm |
| 6060-T6 | 190 MPa | 150 MPa | up to 3 mm |
| 6060-T66 | 215 MPa | 160 MPa | up to 3 mm |
| 6063-T5 | 175 MPa | 130 MPa | up to 3 mm |
| 6063-T6 | 215 MPa | 170 MPa | up to 10 mm |
| 6063-T66 | 245 MPa | 200 MPa | up to 10 mm |
| 6005A-T6 (open profile) | 270 MPa | 225 MPa | up to 5 mm |
Minimum values for extruded profiles summarised from EN 755-2. Limits change with wall thickness band and between open and hollow profiles, and other standards (ASTM B221, GB/T 5237.1, IS 733) set their own values. The mill certificate for each lot states the actual test results.
For typical rather than minimum values, 6063-T5 usually reaches about 185 MPa tensile and 145 MPa yield, and 6063-T6 about 240 MPa tensile and 215 MPa yield (Aluminum Association typical values). The elastic modulus of all these alloys is close to 69 GPa, so stiffness, which usually governs door profile design, depends on the section shape far more than on the alloy or temper. Upgrading from T5 to T6 does not make a door leaf stiffer; a deeper section does.
Door systems are usually described by series, which refers to the overall frame depth in millimetres. A 70 series system has a frame about 70 mm deep; a 100 series about 100 mm. Deeper series allow thicker glazing units, wider thermal breaks and higher stiffness, and they are used for larger and more exposed doors.
| Series (frame depth) | Typical use | Glazing it can take | Notes |
|---|---|---|---|
| 45 – 55 mm | Interior doors, partitions, wardrobes | Single glass 5 – 10 mm, panels | Usually non-insulated |
| 60 – 70 mm | Residential hinged and sliding doors | Double glazing up to about 28 mm | Thermal break with 14.8 – 20 mm polyamide strips common |
| 75 – 90 mm | Insulated residential and light commercial doors | Double or triple glazing up to about 44 mm | Wider strips, foam inserts in chambers |
| 100 – 120 mm and above | Lift-and-slide, large sliding and pivot doors, cold climates | Triple glazing, heavy laminated units | Deep structural sections, reinforced tracks |
Wall thickness is the second key dimension. Thicker walls add strength at screw fixings and hinges, reduce the risk of dents and give the extruder more control over surface quality, but they add weight and cost. Practical guidance used across the industry is:
These figures are guidance, not a substitute for structural calculation. A door leaf or mullion should be checked for deflection under the design wind pressure, normally limited to span/150, span/175 or span/200 depending on the glazing and the code, with an absolute cap (often 15 mm) for insulating glass. Because deflection depends on the moment of inertia, system houses publish Ix and Iy for each profile. When you send a drawing to Metline, include these section properties or the CAD file so we can confirm them.
Weight per metre comes straight from the cross-sectional area: multiply the area in mm² by the density of 2.70 g/cm³ and divide by 1,000 to get kg/m. The table shows quick values for typical door profile areas, with standard 6.0 m and 6.5 m mill lengths.
| Cross-section area (mm²) | kg per metre | 6.0 m length (kg) | 6.5 m length (kg) |
|---|---|---|---|
| 250 | 0.675 | 4.05 | 4.39 |
| 350 | 0.945 | 5.67 | 6.14 |
| 450 | 1.215 | 7.29 | 7.90 |
| 550 | 1.485 | 8.91 | 9.65 |
| 650 | 1.755 | 10.53 | 11.41 |
| 800 | 2.160 | 12.96 | 14.04 |
| 1000 | 2.700 | 16.20 | 17.55 |
| 1200 | 3.240 | 19.44 | 21.06 |
| 1500 | 4.050 | 24.30 | 26.33 |
| 1800 | 4.860 | 29.16 | 31.59 |
Aluminium conducts heat very well: 6063 has a thermal conductivity of roughly 200 W/m·K. A solid aluminium frame therefore acts as a cold bridge, losing heat in winter and causing condensation on the inside face. A thermal break solves this by splitting the profile into an outer and an inner aluminium shell joined by a material of low conductivity.
Glass-fibre reinforced polyamide 6.6 (typically PA66 GF25) strips, with a conductivity around 0.3 W/m·K, are rolled into knurled grooves in the two aluminium shells. The most widely used method. Strip depths range from about 14.8 mm to 34 mm or more; deeper strips give better insulation.
A two-part polyurethane resin is poured into a channel in the profile, cured, and the aluminium bridge beneath it is then cut away. Common in North America. Fast and economical, but the frame must be finished before pouring or with a finish compatible with the process.
Closed-cell foam or extruded insulating inserts placed in the chambers between the polyamide strips cut radiation and convection in the cavity, lowering the frame U-value further. Used in high-performance and passive-house systems.
The frame U-value (Uf) is calculated to EN ISO 10077-2 or measured by hot-box test. As a broad guide, non-insulated aluminium frames are typically above 5 W/m²·K, while thermal-break frames commonly fall between about 1.0 and 3.5 W/m²·K depending on strip depth and inserts. The whole-door value then depends heavily on the glazing and its spacer.
The mechanical connection between the shells is just as important as the insulation. EN 14024 sets out tests for transverse tensile strength and shear strength of the composite at room, low and high temperature, and ageing tests. When you order thermal-break profiles, ask for the strip supplier and EN 14024 test evidence, and confirm whether the profiles will be finished before or after assembly: powder curing at around 180 – 200 °C is compatible with polyamide strips, but the strip grade and curing cycle should be agreed in advance.
The finish defines how the door looks for decades and how well it survives coastal air, pollution and cleaning chemicals. Each option has a recognised quality scheme, and specifying the scheme class is far more useful than asking for "good quality" coating.
| Finish | Typical thickness | Quality scheme / standard | Best suited to |
|---|---|---|---|
| Anodising | 15, 20 or 25 µm (outdoor); 5 – 10 µm interior | Qualanod; EN ISO 7599; AAMA 611 (Class I ≥ 18 µm, Class II ≥ 10 µm) | Metallic appearance, abrasion resistance, silver, bronze and black tones |
| Powder coating (polyester) | 60 – 80 µm, minimum 60 µm | Qualicoat Class 1, 1.5, 2 and 3; AAMA 2603 / 2604 / 2605 | The widest colour range, RAL and textured finishes |
| PVDF (fluorocarbon) | 2-coat about 30 – 40 µm, 3-coat about 40 – 60 µm | AAMA 2605; Qualicoat Class 3 equivalent performance | High-rise, coastal and high-UV sites needing the best colour retention |
| Electrophoretic coating | Anodic film plus about 7 – 12 µm clear or coloured lacquer | Supplier and project specification; national standards | Complex profiles needing a uniform, smooth coating |
| Wood-grain sublimation | Powder base coat with transferred decor film | Powder base to Qualicoat; decor to supplier specification | Timber appearance without timber maintenance |
A practical rule: for inland urban and rural sites, Qualicoat Class 1 powder or 15 – 20 µm anodising is normally adequate; within a few kilometres of the sea or in industrial atmospheres, specify 25 µm anodising, Qualicoat Class 2 or PVDF, and require seaside pretreatment where the coater offers it. Always state the visible faces on the drawing so the extruder and finisher protect them, and ask for protective film on finished profiles before they leave the plant.
Colour consistency matters on large projects. Anodised colour depends on alloy composition and extrusion conditions, so order all visible profiles for one facade in the same alloy, from the same source and, ideally, in one production campaign. For more detail on finish selection, read our surface treatment insight and the anodised extrusions guide.
Two layers of standards apply. Material standards govern the extrusion you buy; performance standards govern the finished door the fabricator makes from it. A profile supplier certifies the first; the system house or fabricator tests and certifies the second, but the profile has to be good enough to let the door pass.
| Standard | What it covers | Who it applies to |
|---|---|---|
| EN 573-3 | Chemical composition of wrought alloys (EN AW-6060, 6063 and others) | Profile supplier |
| EN 755-1 / -2 | Technical conditions for inspection and delivery; mechanical properties of extruded profiles | Profile supplier |
| EN 755-9 | Tolerances on dimensions and form for general extruded profiles | Profile supplier |
| EN 12020-2 | Tighter tolerances for precision profiles in 6060 and 6063, including thermal-break profiles | Profile supplier |
| EN 14024 | Mechanical performance of metal profiles with thermal barriers | Thermal-break assembler |
| ASTM B221 / ANSI H35.2 | Extruded bars, shapes and tubes; dimensional tolerances (North America) | Profile supplier |
| EN 14351-1 | Product standard for external windows and pedestrian doorsets (CE / UKCA marking) | Door manufacturer |
| EN 12207, EN 12208, EN 12210 | Classification of air permeability, watertightness and wind-load resistance | Door manufacturer |
| EN 1191, EN 12400 | Repeated opening and closing test; classification of mechanical durability | Door manufacturer |
| EN ISO 10077-1 / -2 | Calculation of thermal transmittance of doors and frames | System house |
| AAMA/WDMA/CSA 101/I.S.2/A440 | North American fenestration standard for windows, doors and skylights | Door manufacturer |
| EN 16034 | Fire-resistance and smoke-control characteristics of pedestrian doorsets | Fire-door manufacturer |
Older documents sometimes misdescribe these standards: EN 16034 deals with fire and smoke control, not thermal insulation, and EN 12020-2 is a tolerance standard, not a corrosion standard. When a tender quotes a standard, check its current edition and scope before pricing.
Dimensional accuracy decides whether hardware fits, gaskets seal and corners close tightly. EN 12020-2 precision tolerances are the normal reference for 6060 and 6063 architectural profiles; EN 755-9 general tolerances suit structural and hidden members. Claims of "±0.05 mm on every dimension" should be treated with caution: real tolerances depend on the size of the dimension, whether it crosses a hollow, the wall thickness and the circumscribing circle, and are read from the standard's tables or agreed on the drawing.
Door fabricators cut profiles on double-mitre saws, machine hardware cut-outs on copy routers or CNC profile centres, and join corners mechanically. Three joining methods are used:
Aluminium corner cleats are inserted into the profile chambers and fixed by crimping, pinning or screwing, usually with a corner adhesive. This is the dominant method because it works with pre-finished profiles and needs no heat.
TIG or MIG welding of 6063 with 4043 or 5356 filler gives a monolithic corner but burns the finish and softens the heat-affected zone. Used for special frames that are finished after welding, not for standard pre-finished door systems.
Structural adhesives bond cleats, panels and glass. Bonding quality depends on surface preparation and must be validated by the system house; it is normally combined with mechanical fixing on doors.
Handle profiles with care. Store them flat on padded racks, keep protective film on until installation, and avoid contact with cement, lime and plaster, which etch aluminium finishes. Separate aluminium from steel fixings with stainless steel or coated fasteners and isolation washers to avoid galvanic corrosion, especially at coastal sites.
| Criterion | Aluminium | uPVC | Steel | Timber |
|---|---|---|---|---|
| Strength to weight | High; slim frames carry large glass | Low; needs steel reinforcement in large doors | Very high but heavy | Moderate |
| Slim sight-lines | Excellent | Poor | Excellent | Moderate |
| Thermal performance | Good with thermal break | Good | Poor unless insulated | Good |
| Corrosion and rot | Very good with proper finish | Does not corrode | Needs protection | Needs maintenance |
| Finish options | Anodised, any RAL, wood-grain | Limited foils and colours | Painted | Stained or painted |
| Recyclability | Recycled repeatedly without loss of properties | Recyclable but less widely | Recyclable | Biodegradable |
Aluminium is the material of choice where large glass areas, slim frames and long service life are needed: patio sliding doors, bifolds, shopfronts and commercial entrances. Recycled aluminium needs only about 5 % of the energy required for primary metal, and architectural profiles are routinely recovered and remelted at the end of a building's life, which supports environmental assessment schemes.
6063 is the global standard, with 6060 widely used in Europe. Both extrude into complex hollow sections with an excellent surface and anodise evenly. For heavy lift-and-slide or pivot doors, 6005A-T6 or 6063-T66 gives extra strength in the main members.
Main frame, leaf and mullion profiles are typically 1.8 to 2.5 mm, and many specifications set 2.0 mm as a minimum for door members. Hinge and lock zones on commercial doors are often 2.5 to 3 mm. Beads and cover caps can be 1.0 to 1.4 mm. Final sizing should follow a structural check of deflection under wind load.
Yes, if the section is deep enough. Stiffness depends on the profile’s moment of inertia, not the alloy, so large sliding and pivot doors use deep sections with internal webs, reinforced tracks and rollers rated for the leaf weight. The system house sets the maximum leaf size and weight for each profile set.
T5 profiles are cooled from the extrusion press and artificially aged; T6 profiles are fully solution treated and quenched before ageing, so they are stronger. Both have the same stiffness. T5 is common for standard residential doors; T6 or T66 for larger, more heavily loaded doors.
The polyamide strips tolerate normal powder-curing temperatures, so profiles can be coated after assembly, but the strip grade and curing cycle should be agreed with the coater. Alternatively the two aluminium shells can be finished separately, even in different colours inside and out, before the strips are rolled in.
No. Metline supplies the aluminium materials: extruded door profiles, thermal-break profiles, sheet, coil and related sections, finished or in mill condition, to fabricators and system companies worldwide. The doors themselves are fabricated and installed by our customers.
Each shipment includes a mill test certificate to EN 10204 3.1 showing chemistry and mechanical properties, a finish test report for anodised or coated profiles, and a packing list. Third-party inspection can be arranged on request.
Send your profile drawings or system details, alloy, finish and quantities. Our team will confirm dies, tolerances and a delivered price to your site worldwide.
