Copper Winding Wire

copper winding wire

The main grade of copper used for electrical applications is electrolytic-tough pitch copper. This copper is at least 99.90% pure and has an electrical conductivity of at least 101% IACS. ETP copper contains a small percentage of oxygen. If high conductivity copper needs to be welded or brazed or used in a reducing atmosphere, then oxygen-free copper may be used.

Several electrically conductive metals are less dense than copper, but require larger cross sections to carry the same current and may not be usable when limited space is a major requirement.

Aluminium has 61% of the conductivity of copper.The cross sectional area of an aluminium conductor must be 56% larger than copper for the same current carrying capability. The need to increase the thickness of aluminium wire restricts its use in several applications, such as in small motors and automobiles. In some applications such as aerial electric power transmission cables, copper is rarely used