A copper bonded earthing rod is a grounding electrode consisting of a high-purity copper bonded at the molecular level over a steel core. The configuration takes the best of the electrical conductivity and corrosion resistance of copper along with the mechanical properties and low cost of steel. The copper layer, which is usually 70–300 microns thick, provides low resistance and effec... https://www.pioneerpowers.com/copper-bonded-earth-rod.php