A sharp edge is not a wear problem. It is a failure problem, and it happens
under load.
Why the edge is worse than it looks
Where a sling bends over an edge, the force concentrates into a narrow band of
material. Fibre slings are cut; wire rope kinks and breaks wires; chain takes a
point load on one link. The damage happens in the moment the load hangs — not
gradually over time.
And the edge does not need to be knife-sharp. An ordinary plate edge, a weld
bead or a concrete corner is enough.
Protection
- Use edge protection made for the purpose, not whatever is lying about
- It must cover the full width of the sling and stay in place as the load
comes on - Check it has not shifted at the trial lift
- Timber, cardboard and rag are not edge protection — they crush away under load
- For large radii a lifting beam or longer slings can remove the problem
rather than patch it
The other direction
The sling can also damage the load: polished surfaces, paintwork, insulation
and thin sheet take point loading badly. Protection works both ways.
After the lift
A sling that has borne against an edge gets inspected before it goes back.
Cut damage in the edge zone is the most common reason a fibre sling is discarded.
What counts as discardable is in the equipment’s documentation and is assessed at
sakkyndig kontroll — see maintenance.
The capacity is on the sling, not on this page. This section explains the geometry and the method. It states no working load limits and no reduction factors for hitch types — those differ between slings and belong to the equipment's own marking, its certificate, and the assessment made at sakkyndig kontroll. Calculate the force with the calculator; read what the sling will take off the sling. If the two do not agree, the lift does not happen.