6061 is a precipitation hardening aluminium alloy, containing magnesium and silicon as its major alloying elements. Originally called "Alloy 61S," it was developed in 1935. It has good mechanical properties and exhibits good weldability. It is one of the most common alloys of aluminium for general purpose use.
It is commonly available in pre-tempered grades such as 6061-O (annealed) and tempered grades such as 6061-T6 (solutionized and artificially aged) and 6061-T651 (solutionized, stress-relieved stretched and artificially aged)
Aluminum composition calculated as remainder. Information provided by Alcoa and the references. General 6061 characteristics and uses: Excellent joining characteristics, good acceptance of applied coatings. Combines relatively high strength, good workability, and high resistance to corrosion; widely available. The T8 and T9 tempers offer better chipping characteristics over the T6 temper.
Uses: Aircraft fittings, camera lens mounts, couplings, marines fittings and hardware, electrical fittings and connectors, decorative or misc. hardware, hinge pins, magneto parts, brake pistons, hydraulic pistons, appliance fittings, valves and valve parts.
The alloy composition of 6061 is:
Silicon minimum 0.4%, maximum 0.8% by weight
Iron no minimum, maximum 0.10%
Copper minimum 0.15%, maximum 0.40%
Manganese no minimum, maximum 0.15%
Magnesium minimum 0.8%, maximum 1.2%
Chromium minimum 0.04%, maximum 0.35%
Zinc no minimum, maximum 0.25%
Titanium no minimum, maximum 0.15%
Other elements no more than 0.05% each, 0.15% total
Remainder Aluminium (95.85%–98.56%)