Copper-clad steel (CCS), also known as copper-covered steel or the

trademark A trademark (also written trade mark or trade-mark) is a type of intellectual property consisting of a recognizable sign, design, or expression that identifies products or services from a particular source and distinguishes them from othe ...

ed name Copperweld is a bi-metallic product, mainly used in the

wire Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm A wire is a flexible strand of metal. Wire is c ...

industry that combines the high mechanical resistance of steel with the

conductivity Conductivity may refer to: *Electrical conductivity, a measure of a material's ability to conduct an electric current **Conductivity (electrolytic), the electrical conductivity of an electrolyte in solution ** Ionic conductivity (solid state), ele ...

and

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...

resistance of

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

. It is mainly used for grounding purposes, line tracing to locate underground utilities, drop wire of telephone cables, and inner conductor of coaxial cables, including thin hookup cables like RG-174 and

CATV Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadc ...

cable. It is also used in some antennas for RF conducting wires.

History

The first recorded attempt to make copper clad steel wire took place in the early 1860s.''Copper Clad Handbook'', issued by the Duplex Metals Co., Chester, Pennsylvania, at the turn of the 20th century Although for over 100 years people had been suggesting various ways of uniting copper and steel, it was not until the period mentioned that Farmer and Milliken tried wrapping a strip of copper about a steel wire. American engineers in 1883 and again in the 1890s made attempts to produce a copper-steel wire, in one instance at least, by electroplating copper on steel. The Duplex Metals Co. traces its beginning to John Ferreol Monnot between 1900 and 1905. He had been very interested in the work of Mr. Martin in Paris. :"After several years devoted to experimenting, organized the Duplex Metals Company. Prior to his discovery of the process under which this company operates in producing its copper clad, probably almost every other possible way of welding copper and steel together had been tried by Mr. Monnot, but found useless for the purpose."

Uses

Copper-clad steel wire find applications in grounding, connection of ground rods to metallic structures, ground grid meshes, substations, power installations, and lightning arresters. This wire is also sometimes used for power transmission. Copper coated welding wire has become common since wire welding equipment has become popular. Copper-clad steel is occasionally used for making durable radio antennas, where its HF conductivity is nearly identical to a same-diameter solid copper conductor. It is most often used in antennas with long spans of unsupported wire, which need extra strength to withstand high tension which would cause solid copper or aluminum wire to break or stretch excessively.

Properties

The main properties of these conductors include: * Good

resistance of copper * High tensile strength of steel * Resistance against

material fatigue In materials science, fatigue is the initiation and propagation of cracks in a material due to cyclic loading. Once a fatigue crack has initiated, it grows a small amount with each loading cycle, typically producing striations on some parts of ...

Advantages

Since the outer conductor layer is low- impedance copper, and only the center is higher impedance steel, the skin effect gives RF transmission lines with heavy copper-cladding a low impedance at high frequencies, equivalent to that of a solid copper wire. Tensile strength of copper-clad steel conductors is greater than that of ordinary copper conductors permitting greater span lengths than with copper. Another advantage is that smaller diameter copper-clad steel conductors may be used in coaxial cables, permitting higher impedance and smaller cable diameter than with copper conductors of similar strength. Due to the inseparable union of the two metals and the low amount of the more costly one, it deters theft since copper recovery is impractical and thus has very little scrap value. Installations with copper-clad steel conductors are generally accepted as fulfilling the legal specifications for a good

electrical ground In electrical engineering, ground or earth is a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be co ...

. For this reason its use is preferred by industrial companies and utilities when cost is a concern.

References

External links