What Are T-Slot Aluminium Extrusions? T-slot aluminium extrusions are aluminium profiles featuring a T-shaped groove along their length. These grooves allow for quick and easy assembly by sliding bolts, nuts, or connectors into the slots without the need for welding or permanent fixtures. Material: Typically made of 6061-T6 or 6063-T5 aluminium alloys, providing a balance of strength, corrosion resistance, and machinability. Sizes: Standard sizes include 20mm, 30mm, 40mm, 45mm, and more, with variations in slot width (e.g., 5mm, 8mm, or 10mm). Surface Finish: Often anodized for enhanced durability, aesthetics, and corrosion resistance.