MYCO Copper Bonded grounding rods probably offer to the installer the best and most economical earth rods available. They are made molecularly bonding 99.9% pure Electrolytic Copper on to a low carbon steel core to thickness up to 0.35mm. They are highly resistant to corrosion and because the steel used has a very high tensile strength, they can be driven by power hammers to great depths. One common misconnection is that the dia of the rod has a drastic effect on lowering earth resistance. This is not true! Use the most economical rod that sol conditions will allow you to drive. Coupling threads are formed by a rolling process to ensure thread strength and to maintain the durability. The universally used thread rolling process raises the surface of the rod. Thus thread diameter is greater than rod dia.