An aluminum alloy formulated and tempered specifically for high performance mechanical properties. 6061 Defines the chemical composition of the Aluminum alloy. In this case magnesium and silicon are key elements that give 6061 its sound mechanical properties. With better weldability, ductility, and strength than many other aluminum alloy's. "T6" Designates the tempering process. This further refines the properties of the metal to make for an extremely lightweight yet strong material. 6061-T6 Aluminum is one of the most common alloys used in applications requiring high performance in strength-to-weight ratios.