# Aluminium Extrusion 6063-T6 for Facade Systems

> 6063-T6 is an aluminium alloy containing magnesium and silicon, solution heat-treated and artificially aged, and extruded into the profiles that carry glass, gaskets and hardware in a facade. It is chosen because it extrudes into complex thin-walled shapes with a good surface finish; wall thickness and finish class then decide how a given profile performs.

## What it is

The **structural backbone of an aluminium facade**: alloy 6063 in T6 temper,
extruded into hollow and open profiles that carry glass, resist wind and hold
the gaskets, hardware and drainage that make a window work.

## Specification at a glance

| Property | Typical specification |
| --- | --- |
| Alloy and temper | 6063-T6 to IS 733 |
| Ultimate tensile strength | Approximately 215 MPa |
| Wall thickness | Stated explicitly, typically 1.4mm — 3.0mm |
| Anodising | Grade to IS 1868, thickness in microns |
| Powder coat | Resin class named; AAMA 2605 for PVDF |
| Straightness and twist | Tolerance stated on the order |

## What to verify on a supply

- **Wall thickness against the approved section**, measured, not assumed
- **Anodic coating thickness in microns** — commonly 15 micron internal,
  20–25 micron external, higher for coastal exposure
- **Powder coat resin class** on the certificate, not the colour name
- **Temper certificate** for the delivered batch
- **Screw port dimensions**, since hardware retention depends on them

## Why the finish class decides service life

A polyester powder coat and a PVDF powder coat look identical on handover. On a
south or west elevation in India, the polyester chalks and fades within a few
years while the PVDF holds colour for well over a decade. The price difference
at supply is modest; the difference in when the building needs recoating is
enormous, and recoating an installed facade is scaffolding, access and
disruption.

## Where projects go wrong

- **Wall thickness unstated**, so the cheapest quote wins on a thinner section
  that deflects more and holds hardware worse.
- **"Powder coated" with no resin class.** Unenforceable.
- **Anodising thickness unspecified** for a coastal site.
- **Mixing profile families** across one facade, so gaskets and hardware no
  longer match the tested assembly.
- **Dissimilar metal contact** — steel fixings directly against aluminium
  without isolation set up galvanic corrosion at the interface.

## Standards referenced

Alloy and temper under **IS 733**. Anodic coating grades under **IS 1868**.
High-performance organic coating performance to **AAMA 2605**.

## Frequently asked questions

### What do 6063 and T6 actually mean?

6063 is the alloy — aluminium with magnesium and silicon, chosen because it extrudes into complex thin-walled shapes with a good surface finish. T6 is the temper, meaning solution heat-treated and then artificially aged to peak strength. Together they give roughly 215 MPa ultimate tensile strength, which is the working basis for most facade and fenestration profile design in India.

### Does profile wall thickness matter if the section looks the same?

Yes, and it is the most common hidden saving on a cheap quotation. Two profiles can share an identical outer shape and differ substantially in wall thickness, which changes stiffness, deflection under wind, screw-port pull-out strength and hardware retention. The specification should state wall thickness, not just the profile drawing, and delivered sections should be checked against it.

### Anodising or powder coating — which is better?

Anodising converts the surface into a hard oxide layer that is part of the metal, so it cannot peel and wears extremely well, but the colour range is narrow. Powder coating offers any colour, with durability entirely dependent on the resin class: a PVDF system to AAMA 2605 lasts far longer in Indian UV than a standard polyester. Name the class, not just the colour.

## Sources

- [IS 733](https://standards.bis.gov.in/website/published-standards/department-wise) — Wrought aluminium alloy bars, rods and sections
- [IS 1868](https://standards.bis.gov.in/website/published-standards/department-wise) — Anodic coatings on aluminium
- [AAMA 2605](https://fgiaonline.org/) — High-performance organic coatings on aluminium extrusions

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Source: https://hagerstone.com/materials/aluminium-extrusion-6063-t6