ACSR is a composite, concentrically stranded conductors in which the light weight and good conductivity of aluminum are combined with high tensile strength of steel. It is composed of one or more layers of EC grade hard drawn aluminum wires helically stranded around an inner core of high strength zinc-coated steel wires. The inner steel core may be a single zinc-coated steel wire. or concentrically stranded of one or more later of zinc-coated steel wires.

ACSR has long been widely used as overhead high tension transmission lines and has an established reputation of economy and dependability. The illustration below shows typical standard sizes and stranding patterns.