High voltage cable manufacturers generally choose copper as the conductor in wires and cables. Pure copper has a purple red appearance and is called purple copper. The density of purple copper is 8.89g/cm, which has good conductivity and is suitable for use as a conductor in wires. Secondly, copper's conductivity is second only to silver, and the purer the copper, the better its conductivity in wires.
　　
The main properties of copper are as follows:
　　
(1) Good conductivity, with a conductivity of 91.3% of silver.
　　
(2) Good thermal conductivity, with a thermal conductivity of 73% of silver.
　　
(3) Good plasticity, easy to shape and process.
　　
(4) Strong corrosion resistance, hydrochloric acid and dilute sulfuric acid have little effect on copper. It has strong corrosion resistance in dry air and is prone to toxic copper green (alkaline copper carbonate) in humid air containing CO.
　　
(5) It can be made into various alloys with different characteristics with other non-ferrous metal materials.
　　
The conductive copper used in wires and cables is usually industrial copper with a copper purity of 99.9%. Under special conditions, oxygen free copper or non-magnetic highly pure copper can be used as the conductor of the wire.