6063-T5
Cooled at the press and artificially aged. The economical standard for window and door frames, trims and furniture where moderate strength is enough.
Architectural extrusion alloy
6063 Aluminium Extrusion
6063 is the most widely extruded aluminium alloy: it flows easily through complex dies, gives a smooth surface that anodises and powder coats beautifully, and offers moderate strength in the T5 and T6 tempers. Metline supplies 6063 profiles for windows, doors, facades, furniture, trims, LED housings and heat sinks, from standard dies or your own drawing, to customers worldwide.
- Alloy
- 6063 (Al-Mg-Si)
- Tempers
- T4, T5, T6, T66
- Strength T6
- 215 MPa min (EN)
- Finish
- Anodised, powder coated
What makes 6063 the standard extrusion alloy?
6063 is a lean aluminium-magnesium-silicon alloy. Its low alloy content keeps the billet soft at extrusion temperature, so it can be pushed fast through intricate hollow dies with thin walls and sharp detail. The result is a smooth, uniform surface that needs little preparation before finishing.
Strength comes from ageing after extrusion. Because 6063 is not very quench-sensitive, it can be solution treated simply by cooling with air or a light water mist as it leaves the press, then aged in an oven to T5 or T6. That short route is a big reason why 6063 profiles are economical: no separate furnace solution treatment is needed for most sections.
The trade-off is strength. 6063-T6 has roughly 80 % of the yield strength of 6061-T6 and about two-thirds that of 6082-T6, so it is the right alloy for window frames, curtain wall mullions with modest spans, trims, furniture and heat sinks, but not usually for heavy structural members. Its close relative 6060 is even easier to extrude and is common in Europe for the same applications.
6063 chemical composition (wt %)
| Element | Min | Max | Effect |
|---|---|---|---|
| Silicon (Si) | 0.20 | 0.60 | Forms Mg2Si with magnesium |
| Iron (Fe) | — | 0.35 | Kept low for bright anodising |
| Copper (Cu) | — | 0.10 | Impurity; low copper keeps corrosion resistance high |
| Manganese (Mn) | — | 0.10 | Impurity |
| Magnesium (Mg) | 0.45 | 0.90 | Strengthening with silicon |
| Chromium (Cr) | — | 0.10 | Impurity |
| Zinc (Zn) | — | 0.10 | Impurity |
| Titanium (Ti) | — | 0.10 | Grain refiner |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder |
Aluminum Association / EN 573-3 limits for EN AW-6063 (AlMg0.7Si). Extruders often work within a narrower band, for example a richer Mg-Si balance for T6 or T66 profiles.
6063 mechanical properties by temper
| Temper | Min. tensile | Min. yield (0.2 %) | Min. elongation | Standard / basis |
|---|---|---|---|---|
| T4 | 130 MPa | 65 – 70 MPa | 12 – 14 % | EN 755-2 / ASTM B221 |
| T5 (wall ≤ 3 mm, EN) | 175 MPa | 130 MPa | 6 – 8 % | EN 755-2 |
| T5 (wall ≤ 12.5 mm, ASTM) | 150 MPa (22 ksi) | 110 MPa (16 ksi) | 8 % | ASTM B221 |
| T6 (wall ≤ 10 mm, EN) | 215 MPa | 170 MPa | 8 % | EN 755-2 |
| T6 (ASTM) | 205 MPa (30 ksi) | 170 MPa (25 ksi) | 8 – 10 % | ASTM B221 |
| T66 (wall ≤ 10 mm) | 245 MPa | 200 MPa | 8 % | EN 755-2 |
| T5, typical | about 185 MPa | about 145 MPa | about 12 % | Typical |
| T6, typical | about 240 MPa | about 215 MPa | about 12 % | Typical |
Where a profile has several wall thicknesses, the lowest specified value applies. Minimums fall slightly for walls over 10 mm (EN) and the exact band is shown on the mill certificate.
Physical properties (typical)
- Density
- 2.69 – 2.70 g/cm³
- Elastic modulus
- about 69 GPa
- Thermal conductivity
- about 200 – 210 W/m·K (T5 / T6)
- Electrical conductivity
- about 53 – 55 % IACS
- Thermal expansion
- about 23.4 µm/m·°C
- Melting range
- about 615 – 655 °C
6063-T5, T6 and T66: which one?
6063-T6
Fully solution treated (usually by intensive press quench) and aged. About 20 – 25 % stronger than T5; used for curtain wall, handrails, ladders and load-carrying frames.
6063-T66
A higher-strength T6 variant from controlled chemistry and processing. Used where 6063 finish is wanted with strength closer to 6005A.
6063-T4
Naturally aged and soft. For bending and forming, followed by ageing if strength is needed.
6063-T52
Lower-strength temper with stress relief, used for some architectural and electrical sections.
6063-O
Annealed for severe forming such as tight bends and flaring.
Order against the exact temper: T5 and T6 profiles look identical, and only a hardness check or tensile test separates them. Webster or Barcol hardness testing on site is a quick way to confirm that a delivered lot has been aged properly.
Standards and equivalents for 6063 profiles
| System | Designation | Relevant standards |
|---|---|---|
| ASTM / Aluminum Association | 6063 | ASTM B221 (extrusions), ASTM B241 / B429 (tube and pipe) |
| UNS | A96063 | — |
| European | EN AW-6063 (AlMg0.7Si) | EN 755-2 (properties), EN 755-9 and EN 12020-2 (tolerances), EN 15088 (construction products) |
| ISO | AlMg0.7Si | ISO 6362 |
| Japan | A6063S | JIS H4100 |
| India | 63400 (formerly HE9) | IS 733, IS 1285 |
| Finishing | — | Anodising to EN ISO 7599; powder coating to Qualicoat or AAMA 2603 / 2604 / 2605 classes |
Anodising, powder coating and other finishes
Surface quality is the main reason to choose 6063, so state finishing requirements as clearly as mechanical ones: which faces are visible, the finish and colour, the film thickness or coating class, and how profiles must be protected in transit.
| Finish | Typical specification | Good for |
|---|---|---|
| Clear or colour anodising | 10 – 25 µm film; 15 – 20 µm for exterior architecture, 25 µm in aggressive environments | Windows, facades, trims, consumer products |
| Hard anodising | 25 – 60 µm, Type III | Wear surfaces, slides and tracks |
| Powder coating | 60 – 120 µm polyester; architectural classes to Qualicoat or AAMA | Colour-matched architecture, furniture |
| Wood-grain transfer | Powder base with sublimated pattern | Windows and decorative interiors |
| PVDF / liquid coating | Multi-coat fluoropolymer | High-durability facades |
| Brushed, polished, electrophoretic | Mechanical finish plus anodising or clear coat | Premium furniture and electronics |
Extrusion die lines run lengthwise and are usually invisible after a matt etch. Bright-dip and polished finishes need extra care in die maintenance and handling, so mention them at the quotation stage.
Where 6063 extrusions are used
- Windows and doors: sliding, casement and thermal-break frames, sashes and beads
- Curtain wall and facades: mullions, transoms, pressure plates and cover caps
- Interiors and furniture: partitions, shelving, cabinet handles, wardrobe and kitchen profiles
- Lighting: LED strip channels, linear luminaire housings and diffusers
- Electronics: heat sinks and enclosures, where 6063 conducts heat about 20 % better than 6061
- Transport interiors: trims, luggage racks and panel joiners
- Handrails, balustrades and ladders: in T6 for extra strength
- Irrigation and general tube: drawn or extruded 6063 tube for frames and fluids
6063 vs 6060, 6061 and 6082
| Property | 6060-T6 | 6063-T6 | 6061-T6 | 6082-T6 |
|---|---|---|---|---|
| Min. tensile (EN, thin walls) | 190 MPa | 215 MPa | 260 MPa | 290 – 310 MPa |
| Min. yield (EN, thin walls) | 150 MPa | 170 MPa | 240 MPa | 250 – 260 MPa |
| Extrusion speed | Fastest | Very fast | Medium | Medium |
| Anodised appearance | Excellent | Excellent | Good | Good |
| Typical use | Windows, trims (Europe) | Architecture, heat sinks | Structures, machined parts | Structures (Europe) |
Choose 6063 when appearance and complex shape matter most and loads are moderate. Move to 6061 or 6082 when the profile carries significant structural load. See 6061 vs 6063 for a detailed comparison.
How to order 6063 extrusions
- SpecifyDrawing or die number, temper (T5, T6, T66), length, quantity, standard (EN 755, ASTM B221) and visible faces.
- FinishFinish type, colour reference, film or coating thickness and protective film or interleaving.
- ApproveNew dies are sampled and dimensionally checked; colour samples are approved for anodised or coated profiles.
- Produce and inspectExtruded, aged, finished and checked for dimensions, hardness and finish; EN 10204 3.1 certificate supplied.
- ShipPaper-interleaved, film-wrapped bundles in export cases or containers on EXW, FOB, CIF or DAP terms.
References and standards
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- EN 12020-2 – Extruded precision profiles in alloys EN AW-6060 and EN AW-6063: tolerances
- EN ISO 7599 – Anodizing of aluminium and its alloys: decorative and protective anodic coatings
- The Aluminum Association – alloy registration and Aluminum Design Manual
6063 aluminium (aluminum) extrusion: frequently asked questions
What is the difference between 6063-T5 and 6063-T6?
T5 is cooled at the press and aged; T6 is fully solution treated, quenched and aged. Under EN 755-2, T6 profiles (walls up to 10 mm) have a minimum of 215 MPa tensile and 170 MPa yield, against 175 MPa and 130 MPa for T5 in thin walls. T5 is fine for windows and trims; T6 suits load-carrying frames.
Is 6063 strong enough for structural use?
For light structures such as window frames, curtain wall with moderate spans, handrails and furniture, yes. For beams, platforms and heavily loaded frames, 6061 or 6082 is the better choice.
Why is 6063 used for heat sinks?
It extrudes into thin, closely spaced fins and conducts heat at about 200 – 210 W/m·K, better than 6061. It also anodises well for improved emissivity.
Can 6063 be welded and bent?
Yes. It welds well with ER4043 or ER5356 filler, though the weld zone loses strength. For bending, T4 or O temper gives the tightest radii; T5 and T6 can be bent to moderate radii.
What is the Indian equivalent of 6063?
IS 63400 (formerly HE9) under IS 733 is the commonly used close equivalent. Confirm the governing standard on your drawing.
Do you supply 6063 profiles finished and cut to length?
Yes. Metline supplies 6063 profiles anodised, powder coated or mill finish, cut to length and protected with film for transport, worldwide.
Need 6063 profiles?
Send the drawing, temper, finish and quantities. We will reply with die, finish and delivery details and a delivered price.
