BSD series Copper Bonded Ground Rods are made of high-quality Steel  core coved with 99.9% electrolytic copper molecular. The thickness of surface copper plated layer is 0.25mm. Molecular bond with steel core surface is formed by electroforming process, which is highly conglutinated (tight bond and have rolled screw thread).
Steel cores are required diameters rods with tensile strength being as high as 600N/mm2 so that earth rods can easily get to deep underground by impact. It is ensured that earth rod can be used at least fifty years.