Aluminium Extrusion 6063-T6 for Facade Systems

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.