Construction of Wire Rope
Construction of Wire Rope. The basic unit of wire-rope construction is the individual wire made of steel or other metal in various sizes. These wires are laid together to form strands. The number of wires in a strand varies according to the purpose for which the rope is intended. A number of strands are laid together to form the wire rope itself.Wire rope is designated by the number of strands per-rope and the number of wires per strand. Thus, a 6 X 19 rope has 6 strands with 19 wires per strand, but has the same outside diameter as a 6 X 37 wire rope, which has6 strands with 37 wires of much smaller size per strand.Wire rope made up of a large number of small wires is flexible, but the small wires break so easily that the wire rope is not resistant to external abrasion. Wire rope made up of a smaller number of larger wires is more resistant to external abrasion, but is less flexible.The strands of the wire rope are laid up around a central core, which may be fiber, a single strand of wire,or an independent wire rope. A fiber core contributes flexibility, cushions the strands as the wire rope contracts under strain and holds a portion of lubricant for continuous lubrication. A wire core is stronger than fiber core and can be used where conditions such as-high temperatures would damage the fiber. Some end views of the arrangements of strands in wire ropes are shown in figure.