Aluminium tee-sections
1985 Edition

The standard designates specific aluminium alloys and their temper states for tee-sections, generally including alloys like 6061 and 6063 known for their strength and corrosion resistance. Typical tempers specified are T6, representing solution heat-treated and artificially aged condition for enhanced strength, and T5, denoting cooled from elevated temperature shaping and artificially aged for moderate strength. These alloys and tempers provide a balanced combination of mechanical performance and durability suitable for structural applications.

Aluminium tee-sections are defined by their depth (height), flange width, and mass per unit length as specified in the standard’s dimensional tables. Sectional properties include cross-sectional area, moments of inertia about principal axes, radii of gyration, and section moduli. These dimensions typically range from depths of approximately 50 mm up to 200 mm with proportional flange widths and thicknesses, enabling engineers to select suitable sections based on structural requirements.

The designation format follows the pattern: ALT [depth] × [flange width] - [mass in kg/m], for example, ALT 125 × 100 - 7.0. Each tee-section must be marked clearly with this designation along with the alloy and temper details, manufacturer’s name, and batch or year of production. This marking ensures traceability and confirms conformity to the standard, facilitating quality control and identification in the supply chain.

Dimensional tolerances for aluminium tee-sections generally conform to standards for aluminium extrusions, allowing for variations typically within ±1% to ±2% of nominal dimensions for depth and width, ±0.2 mm for thickness, and ±5 mm for length. As the standard references related aluminium section standards for tolerances, precise values should be verified with the manufacturer or applicable codes like IS 1285 to ensure compliance with quality and fit requirements.

While the standard does not explicitly mandate a root radius for aluminium tee-sections, good engineering and manufacturing practice recommend incorporating a fillet radius at the junction of the flange and web to reduce stress concentration and enhance durability. The inclusion of a small root radius, often in the range of 1 to 2 mm, is advisable to improve the structural performance and longevity, even though the absence of it is not prohibited by the specification.