The Basic Elements of Steel Wire Rope

rope technology fig 1A steel wire rope normally consists of three components (fig. 1):

  • Steel wires that form a strand
  • Strands that are wrapped around a core
  • The core

These elements are available in various models / designs, depending on the physical requirements of the steel wire rope and its intended application. A single strand can in certain cases be used quite properly as a steel wire rope.

A fourth component, that is equally as important for the steel wire rope’s performance as the design and quality of the three basic components, is the lubrication of the core and the strands (see “Maintenance of Steel Wire Rope”).

Steel wire

There are many different types of material and qualities of steel wire. Randers Reb can supply most of these qualities – contact us to find out how Randers Reb can meet your own particular needs.

The steel qualities that Randers Reb uses in the production of standard steel wire rope as a minimum requirement meet international standards (EN 10264). In this way Randers Reb’s steel wire ropes achieve a high degree of uniformity.

The minimum tensile strength of the steel wire defines the classification of the steel wire rope. The tensile strength of high quality steel wires in Randers Reb’s standard product range is as follows:

  • Ungalvanised wires (mainly elevator cables)
    1,370 N/mm² (140 kp/mm²).
  • Zinc galvanised wires (mainly fishing)
    1,570 N/mm² (160 kp/mm²).
  • Zinc/alum. galvanised wires (mainly fishing)
    1,570 N/mm² (160 kp/mm²).
  • Stainless steel wires, tensile strength dependent on size
    1,670 N/mm² (170 kp/mm²).
  • Zinc galvanised wires (mainly industry)
    1,770 N/mm² (180 kp/mm²).
  • Zinc galvanised wires (mainly industry)
    1,960 N/mm² (200 kp/mm²).

Randers Reb always demands that all wire consignments are accompanied by a wire certificate.

Strands

A strand is laid by a minimum of three wires that are arranged in many different designs (geometric patterns). The strand is almost always arranged around a centre wire. The wires are made from either steel or fibre (natural or man-made), or a combination of these.The quantity, size and material from which the individual wires are made characterise the rope and its qualities. Fewer, thicker wires create greater abra- sion resistance, whereas a greater number of thinner wires creates greater flexibility (see also “Types of Strand”, page 8-3).

Core

Almost all steel wire ropes have a core. The core’s function is to support and retain the strands in their respective positions while the steel wire rope is being used.

rope technology fig 2

The core may be made of either steel, fibre, or a combination of the two. (fig. 2) The core is usually one of the following types:

  • FC (natural or man-made fibre, Fibre Core).
  • WSC (steel core, Wire Strand Core). The WSC is a strand and is of exactly the same construction as the strands in the steel wire rope.
  • IWRC (steel core, Independent Wire Rope Core).

The IWRC is an independent steel wire rope with a fibre core or a WSC (see also ”Types of Core”, page 8-6).