Code of Federal Regulations Title 30. Mineral Resources § 30.75.1434 Retirement criteria

(a) The number of broken wires within a rope lay length, excluding filler wires, exceeds either—

(b) On a regular lay rope, more than one broken wire in the valley between strands in one rope lay length;

(c) A loss of more than one-third of the original diameter of the outer wires;

(d) Rope deterioration from corrosion;

(e) Distortion of the rope structure;

(f) Heat damage from any source;

(g) Diameter reduction due to wear that exceeds six percent of the baseline diameter measurement;  or

(h) Loss of more than ten percent of rope strength as determined by nondestructive testing.