At what level of wear should a wire rope be scrapped?
1 Answers
GB6067-2010 "Safety Regulations for Lifting Appliances" specifies the following criteria for scrapping wire ropes: 1. When the number of broken wires within one lay length reaches 10% of the total wires in the rope: For example, a 6×19=114-wire rope should be scrapped and replaced when 12 wires are broken, and a 6×37=222-wire rope should be scrapped when 22 wires are broken. For wire ropes composed of both thick and thin wires, the calculation is one thin wire counts as one, and one thick wire counts as 1.7. 2. If radial wear or corrosion exceeds 40% of the original diameter, the rope should be scrapped: If it is less than 40%, the number of broken wires can be reduced proportionally for scrapping. 3. For wire ropes used in lifting hot metals or hazardous materials, the scrapping standard is half the number of broken wires compared to general lifting wire ropes. 4. For wire ropes conforming to ISO2408 (Characteristics of wire ropes for general purposes), the number of broken wires for scrapping should follow the standards specified in GB5972—86. 5. If an entire strand breaks, the rope should be scrapped. 6. If the diameter of the wire rope decreases by 7% or more compared to the nominal diameter, the rope should be scrapped even if no broken wires are found. 7. If the core is exposed, the rope should be scrapped. 8. If the wire rope shows obvious corrosion, it should be scrapped. 9. If the outer wires locally elongate and form a birdcage shape, the rope should be scrapped.
