A load-bearing component of cables, particularly aerial and riser cables, designed to increase the overall tensile strength of the cable and to relieve the wires and fibers from bearing the load directly. As optical fiber, in particular, stretches very little before breaking, the strength members also must Conductor Jacket Shields Insulation have very low elongation at the expected tensile loads.The strength members in optical fibers commonly are of aramid fiber yarn, invented and marketed by Dupont as Kevlar