Overview

6061 aluminum (Unified Numbering System (UNS) number A96061) is a precipitation-hardening aluminum alloy containing magnesium and silicon as its main alloying elements. Originally called "Alloy 61S", it was developed in 1935. It has good mechanical properties, good weldability, and is very commonly extruded (second only to 6063). It is one of the common general-purpose aluminum alloys.

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

6061 is commonly used in the following applications:

Construction of aircraft structures, such as wings and fuselages. 2024 alloy is slightly stronger, but 6061 is easier to machine and maintains corrosion resistance even if the surface is worn, which is not the case with 2024, which is often used with a thin coating to improve corrosion resistance. Yacht construction, including small multi-purpose boats; automotive parts; flashlights; aluminum cans for packaging food and beverages; gas cylinders; bicycle frames and components; parts of remote control model aircraft, especially helicopter rotor parts; fire rescue ladders, etc.

Welding

6061 is highly weldable, for example using tungsten inert gas (TIG) or metal inert gas (MIG). Typically, after welding, the properties near the weld are those of 6061-T4, with a strength loss of about 40%. The material can be reheat treated to restore the entire piece to a near-T6 temper. After welding, the material is allowed to age naturally and recover some of its strength. Most of the strength is recovered within the first few days to weeks.

Extrusions

6061 is an alloy used to produce extrusions - long, constant cross-section structural shapes produced by forcing metal into a forming die.

Forgings

6061 is an alloy suitable for hot forging. The billet is heated through an induction furnace and forged using a closed die process. This special alloy is suitable for open die forgings. Auto parts, ATV parts, and industrial parts are just some of the uses for forgings. Aluminum 6061 can be forged into flat or round bars, rings, blocks, discs and blanks, hollows, and ingots. 6061 can be forged into special and custom shapes.

Castings

6061 is not a traditionally cast alloy because its low silicon content affects casting fluidity. It can be properly cast using a specialized centrifugal casting method. Centrifugal cast 6061 is ideal for larger ring and sleeve applications that exceed the limits of most forged products.