Wear of what fraction of the original diameter of the outside wires indicates replacement?

• A. 1/4
• B. 1/3
• C. 1/2
• D. 2/3

Answer: (B)

In wire rope inspection, wear on the outside wires is the first and most critical indicator because those wires take the most bending and abrasion. When the outside wires have worn down to one-third of their original diameter, the rope’s remaining strength is significantly reduced, making replacement the safer choice before a failure occurs. In practice, inspect straight sections and compare the diameter of the outer wires to their original size; if any outer wire is down to one-third or less, replace the rope. The other fractions are not the standard threshold for replacement.