IS 1285 covers extruded aluminium tubes and hollow sections — the base material for aluminium windows, curtain walls, handrails, and structural frames. Grade 63400-T6 (equivalent to AA 6063-T6) is the most widely used architectural aluminium alloy in India.
Specification for extruded aluminium tubes and hollow sections covering alloys, tempers, dimensions, mechanical properties, and surface quality.
Key Values
63400-T6 yieldMin 170 MPa
63400-T6 tensileMin 205 MPa
63400-T6 elongationMin 8%
Practical Notes
! Grade 63400-T6 (AA 6063-T6) is the standard for window/door sections — good extrudability, anodizability, and strength.
! T6 temper means solution treated + artificially aged — gives the best strength. T4 is weaker.
! Always check wall thickness of extruded sections — thin walls (<1.2mm) may not meet structural requirements.
! Anodized finish (IS 1868) provides better corrosion resistance and appearance than mill finish.