6061

6061 is a precipitation-hardened aluminum alloy in the 6000-series, produced by alloying aluminum with magnesium and silicon. It offers a well-balanced combination of strength, light weight, corrosion resistance, and good machinability, making it one of the most widely used aluminum alloys. The major alloying elements are magnesium (0.8–1.2%) and silicon (0.4–0.8%), with small amounts of iron, copper, chromium, zinc, and manganese; aluminum is the remainder. Standard temper designations include O (annealed), T4 (solution heat-treated and naturally aged), T6 (solution heat-treated and artificial aged), and T651 (stress-relieved by stretching).

Mechanical properties vary by temper. In the popular T6 temper, yield strength is typically around 240–290 MPa and ultimate tensile strength around 290–350 MPa, with elongation generally in the 10–14% range. Other tempers offer higher formability but lower strength. 6061 also displays good corrosion resistance in most environments and anodizes well.

6061 is widely available in wrought forms such as extruded profiles, rods, bars, plates, and sheets. Fabrication includes machining, welding, and forming; welds are generally sound but may require post-weld aging or heat treatment to regain full strength. It is a common choice for bicycle frames, aerospace and automotive structural components, marine parts, and general structural extrusions.

Standard uses include structural components in aircraft and vehicles, plumbing fittings, and architectural applications. Its balance of properties plus availability and cost keeps 6061 a default option among the 6xxx aluminum alloys.