Inspection of Rigging Before Use
Inspection is a decision, not a routine
Pre-use inspection is a go/no-go judgment made before every lift. The user inspects each sling, shackle, hook, and below-the-hook device at the start of the shift and again after any dropping, shock loading, or exposure to heat or chemicals. A qualified person performs periodic and annual inspections and keeps records. The tag carries the sling's type, reach, and rated capacity: no legible tag means out of service - no guessing and no matching by appearance.
What you are looking for
Removal criteria fall into a few families:
- Wire rope: broken wires (10 randomly broken in one lay, or 5 broken in one strand in one lay), kinking, crushing, bird-caging, corrosion, heat discoloration, damaged fittings.
- Chain: cracks, nicks, gouges, elongation, bent or twisted links, worn or opened hooks.
- Synthetic web: cuts, tears, snags, burns, ultraviolet glazing, broken or worn stitching, embedded grit, and knots.
- Hardware: cracks, deformation, damaged threads, and wear exceeding 10% of the original dimension.
- Hooks: throat opening increased more than 10% or 1/4 in, whichever is greater, or twist exceeding 10 degrees.
Traps: questions often describe a sling that "looks fine" but has a missing tag, a field-sewn repair, or a knot - all are removal criteria. Welding, straightening, or otherwise repairing a bent hook or shackle is never acceptable.
Rule of thumb
Compare to the original dimension, never to a guess. New hook throat 2.00 in: the limit is the larger of 0.20 in and 0.25 in, so remove the hook at 2.25 in.