30 C.F.R. § 77.1434 — Retirement criteria.
§ 77.1434 Retirement criteria. Unless damage or deterioration is removed by cutoff, wire ropes shall be removed from service when any of the following conditions occurs: (a) The number of broken wires within a rope lay length, excluding filler wires, exceeds either— (1) Five percent of the total number of wires; or (2) Fifteen percent of the total number of wires within any strand; (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.