Earth Rod with plated 99.9% pure copper production process, good conductivity,corrosion resistance and higher tensile strength ... . 1. The Steel Round Bar copper layer thickness: >=0.254mm2. Resistivity: <=0.05ohm/mm3. ... cost of earth rod.5. The copper layer plasticity: the copper earth rods bent 180°, copper layer without cracks, without sheddingphenomenon,So ...