Comparison of the Discard Criteria in the Regulations of Different Countries
RoundTable – WIRE ROPE DISCARD CRITERIA - Zurich 1989
The discard criteria of ISO 4309 (draft) being the worldwide valid standard for cranes and lifting appliances correspond with DIN 15020. The standard contains a list of 12 different criteria for the critical examination of the operating safety of crane ropes. In national standards (instructions) for different kinds of application of ropes (cranes, elevators, mines, ropeways) there is in each only a part of the 12 criteria of ISO 4309. The admissible number of broken wires, the admissible reduction of cross-sectional area by corrosion or wear and the admissible reduction of diameter differ depending of the kind of application. Sometimes the standards (instructions) classify the number of broken wires for ordinary lay and Lang's lay, but not for the kind of core (fibre core / steel core).
Author: W. Beck