Copper Clad Steel (CCS) is a bimetallic material containing a low carbon steel core surrounded by copper. The copper provides the electrical conductivity and the steel contributes strength to the conductor. The most common grade of CCS used for electrical conductors has a nominal 40% IACS electrical conductivity. CCS is suitable for applications where high strength and medium conductivity are required. Copper Clad Steel also suites high frequency signal applications since high frequency currents travel mainly on the surface of a conductor.