This is the most commonly used discard criteria. ISO 4309:2011 list the number of breaks in the load bearing wires in outer strands needed to determine the discard criteria. The number of visible broken wires are able to be counted in that area of the rope where most of them are present. The length of the area has been determined to be 6d or 30d (“d” = nominal rope diameter).
The rope must be discarded whenever the number of broken wires counted, in 6d or 30d, is equal to, or greater than, those listed in the standards.
When a strand breaks, the rope must be immediately discarded.
REDUCTION OF THE ROPE’S DIAMETER (INTERNAL WEAR)
When the real diameter of the rope is reduced by the 15% from the nominal diameter as a result of internal wear, then the rope has reached discard criteria. The steel wire ropes with a high metallic cross-sectional area have a very stable diameter
ABRASION (OUTER WEAR)
The rope has reached discard criteria when its diameter has reduced by 10% from the nominal diameter due to abrasion of its surface.
DEFORMATION OF THE ROPE
The rope must be discared if showing deformations like bird-caging, flatterings, kiks, bends, and so on…