The stranded All Aluminium Conductor (AAC) are made up of concentric-lay-stranded aluminium wires only.
The conductor may be made up of 7, 19, 37, 61 or more wires in 1, 2, 3, 4 or more layers arounda central wire. Each successive layer shall have six more wires than the layer immediately beneath. For a given crosssectional area, the conductor becomes more flexible as the number of wires is increased(with a corresponding decrease in size of each wire).
When All Aluminium Conductors are to be used in overhead lines, full hard drawn temper wires are used. The illustration below show some typical stranding patterns.