Cables are a construction of wire strands, laid (i.e. twisted) helically around a core, to form a tension member of symmetrical cross section. Cables have a high strength-to-weight ratio as the wire strands are drawn to high strengths and laid to share tensile loads efficiently. There are two fundamental cable constructions: Wire rope (“flexible construction”) and structural strand (“stiff construction”). The construction and subsequent mechanical properties are determined by the wire pattern and wire size used for the core and outer strands.