TEUFELBERGER is the specialist when it comes to manufacturing high-performance steel-wire ropes for cranes, ropeways, and forestry applications. In connection with the use of our products, your safety always figures as our number one priority. Consequently, the number of wire breaks of a rope represents one of several attributes looked at when inspecting your products. Contrary to other discard criteria, the allowable number of wire breaks is design-dependent and therefore needs to be defined specifically for each rope.

Discard criteria

  • Type and number of wire breaks
  • Broken wires at rope end
  • Local frequency of wire breaks
  • Growth rate of wire breaks
  • Strand rupture
  • Reduction of rope diameter, also due to core damage
  • Reduction of elasticity
  • External and internal wear
  • External and internal corrosion
  • Deformation
  • Damage caused by heat or electrical arcs
  • Increase in plastic deformation

Type and number of wire breaks

  • Single-layer or multi-layer winding
  • Ordinary lay or Langs lay design
  • Number of maximum wire breaks on 6xd or 30xd
  • Rope category number

The number of allowable wire breaks to ISO 4309:2004 AMD.1:2008 depends on:

  • Single-layer or multi-layer winding: for multi-layer winding, a greater number of wire breaks is allowable
  • Ordinary lay or Langs lay design: contrary to the point-like contact in the case of an ordinary lay rope, Langs lay ropes are characterised by surface contact between the strands; this results in a reduction of wire breaks
  • Drive mechanism group: see DIN 15020, sheet 1 – § 4.1
  • Maximum number of wire breaks: 6 x rope diameter or 30 x rope diameter (the area where the critical number occurs is decisive)
  • Rope category number (RCN): the classification depends on the number of load-bearing wires contained in the outer strands of a rope (filler wires do not count toward this number)

As a long-standing supplier of ropes, our rope recommendations are non-binding empirical values. Please be sure to also take the specific characteristics of your system into account. Do not hesitate to contact us and we will help you find the ideal rope for your needs.