Copper-clad steel (CCS) is the result when steel wires are metallically bonded with a copper coating to create a wire with the mechanical strength of steel and the corrosion-resistant and conductive nature of copper. CCS is made almost exclusively as wire, and those wires — as a result of the effectiveness of copper-clad steel — are found in telephone cables, grounding wires and power installations. Most CCS wires are made to be from 20 percent to 40 percent conductive, depending on the needs of the project. The two metals are considered to be married, meaning it is considered impossible to separate the copper from the steel, so CCS is theft-resistant.
Metallic wires are needed for many electrical applications, such as for grounding and power installations. The metal in these wires needs to be strong to resist weathering and to remain durable in spite of the high amount of usage. It also needs to be conductive so that electricity can freely flow through the metal and reach its destination. Steel is high-strength but has low conductivity, while copper is the opposite. By marrying the two, copper-clad steel is able to perform both duties by taking advantage of each metal’s strength.
The design of copper-clad steel is rather simple. First, a bare steel wire — usually with low-carbon to keep the steel malleable — is produced. After the steel wire is made, copper is melted and used to coat the wire, bonding the two metals. The bond is so strong that it is known as a marriage, because the metals cannot be separated.
Advantages associated with using copper-clad steel are varied. The steel content means CCS wires have high mechanical and tensile strength and the material fatigue from use is slight. The copper makes the steel, and the entire wire, resist corrosion, so the wire can last much longer, even if it is constantly used. Copper also is very conductive, meaning electricity can easily flow through the wire. Most companies that make CCS wires use copper that is from 20 percent to 40 percent conductive, making it a versatile wire.
One of the interesting advantages to using copper-clad steel is that the wire resists theft. While copper is not the most valuable metal, copper wire is often stolen so the thieves can sell the copper and make a small profit. If an item uses copper bonded to another metal, then these thieves use acids to separate the copper. Copper-clad steel cannot be separated, leaving no reason to steal it, because the wire itself has very little monetary value.