The Least You Need to Know About Aluminum for Machining

cast aluminum part machined

Alum 6061

Aluminum 6061 is one of the most widely used alloy materials in machining due to its price, strength and versatility. Though Aluminum 2024 has a higher strength to weight ratio, it is not as corrosion resistant.

The ability of aluminum 6061 to withstand corrosion makes it economical because it doesn’t require finishing. Once exposed to the atmosphere, it develops a thin protective layer that protects it from surface rust.

The combination of corrosion resistance and low weight make it an economical material to use in short production runs because parts can be created faster. In addition, it is chemical resistant and easy to machine.

Parts that require multiple processes, such as machining and then welding, benefit from Aluminum 6061 because in addition to being easy to machine it is also weldable.

Aluminum 6061 Tempers

There are a variety of tempers for 6061 aluminum alloy, including:

  • 6061-F:

    No special treatment

  • 6061-O:

    Annealed, good for forming

  • 6061-T1:

    Cooled and naturally aged

  • 6061-T4, 6061-T4511:

    Heat-treated and naturally aged

  • 6061-T51:

    Cooled and artificially aged

  • 6061-T6, 6061-T6511:

    Heat-treated and artifically aged, most common alloy used in a variety of applications

  • special tempers: 


Aluminum 6061 Composition

Aluminum 6061 is composed of the following elements by percentage of weight:

  • Magnesium (0.8-1.2)
  • Silicon (0.4-0.8)
  • Iron (Max 0.7)
  • Copper (0.15-0.4)
  • Zinc (Max 0.25)
  • Titanium (Max 0.15)
  • Manganese (Max 0.15)
  • Chromium (0.04-0.35)
  • Other (0.05)
  • Aluminum (balance)

aluminum 6061 infographic: tempers, common forms, composition, applications

Aluminum 6061 Characteristics

Alloy Temper Formability Machinability Corrosion Resistant Weldability (Arc with Inert Gas) Brazeability Anodizing Response
6061 O Very High Poor Very Good Excellent Excellent N/A
6061 T1, T4, T4511 High Fair Very Good Excellent Excellent Very Good
6061 T6, T6511 Low Good Very Good Excellent Excellent Excellent

Aluminum 6061 Applications

  • aircraft wings and fuselages, not as strong as Alum 2024 but more corrosion resistant
  • boats
  • automotive parts
  • flashlights
  • cans
  • tactical flashlights
  • SCUBA tanks made after 1965
  • bicycle frames and parts (T6)
  • fly fishing reels (T6)
  • firearms (T6)
  • RC aircraft (T6)
  • welding
  • extrusions
  • forgings

For More Information About Aluminum

Fun facts from Chemicool

The Aluminum Association

Aluminium International Today