The resistivity Rho of copper is 0.018 at a high degree of purity, and the conductivity is `56.0*10^6` S/m at 20 °C. Copper is nearly as good as silver in conductivity, but it is much more expensive. In addition, the high thermal conductivity of approx. 350 W/mK, the good to very good soldering properties and the equally good corrosion resistance of copper should also be mentioned.
Because of these outstanding properties and because of its flexibility and good thermal conductivity, copper is used primarily or exclusively in metallic conductors ofcables, data cables, stranded wires, in connector pins, conductor tracks, grounding systems and heat sinks, both in bare form and tin-, silver- and nickel-plated.