6061 is a age-hardened aluminum alloy, containing magnesium and silicon as its major alloying elements. It has good mechanical properties, exhibits good weldability, and is very commonly extruded (second in popularity only to 6063). It is one of the most common alloys of aluminum for general-purpose use.

It is commonly available in pre-tempered grades such as 6061-O (annealed), tempered grades such as 6061-T6 (solutionized and artificially aged) and 6061-T651 (solutionized, stress-relieved stretched and artificially aged).

6061 is commonly used for the following:

• construction of aircraft structures, such as wings and fuselages, more commonly in homebuilt aircraft than commercial or military aircraft. 2024 alloy is somewhat stronger, but 6061 is more easily worked and remains resistant to corrosion even when the surface is abraded, which is not the case for 2024, which is usually used with a thin Alclad coating for corrosion resistance.
• yacht construction, including small utility boats.
• automotive parts, such as the chassis of the Audi A8.
• flashlights
• aluminum cans for the packaging of food and beverages.
• Scuba tanks and other high pressure gas storage cylinders.

6061-T6 is used for:

• bicycle frames and components.
• many fly fishing
• the Pioneer plaque was made of this alloy.
• the secondary chambers and baffle systems in firearm sound suppressors (primarily pistol suppressors for reduced weight and improved mechanical functionality), while the primary expansion chambers usually require 17-4PH or 303 stainless steel or titanium.
• The upper and lower receivers of many non mil-spec AR-15 rifle
• Many aluminum docks and gangways are constructed with 6061-T6 extrusions, and welded into place.
• Material used in some ultra-high vacuum(UHV) chambers
• Many parts for remote controlled model aircraft, notably helicopter rotor
• Large amateur radio