Flat & Round Slings

The WLL on the tag is for a straight vertical lift. A choke hitch grips the load but reduces capacity, commonly to about 80% of the tag figure. A basket hitch can carry more than the tag figure because two parts of the sling share the load, provided the legs stay near vertical. The tag or the maker's chart gives the factors. Don't guess them.

No tag, no lift. If the tag is missing or unreadable, the sling has no rating and comes out of service. Same for cut edges, exposed core yarns on a round sling, chemical damage or heavy UV fade. Synthetic slings are cut-prone, so pack sharp corners and use protective sleeves where the load has edges.

Australian synthetic slings are colour coded by working load limit. The relevant standards are AS 1353 for flat webbing slings and AS 4497 for round slings.

The colour is the quick check. The tag is the rating, and a sling without a legible tag has no rating at all.

For a two-leg lift, or a basket hitch with spread legs, capacity falls as the included angle between the legs grows.

Pure geometry: the factor is twice the cosine of half the included angle. The sling tag or the maker's chart is what governs a real lift, and choke or basket factors apply on top of the angle.

Capacity. Violet is 1 tonne, green 2t, yellow 3t, grey 4t, red 5t, brown 6t, blue 8t, orange 10t and above. Always confirm against the tag. The colour is the quick check, the tag is the rating.

Yes. Choking commonly brings a synthetic sling down to about 80% of its tagged capacity. The sling tag or the manufacturer's load chart gives the exact factor.

Missing or unreadable tag, cuts or chafe through the outer, visible core yarns on a round sling, heat glazing, chemical attack or heavy UV fade. Any one of those and it's done. There is no repairing a soft sling.

Before every use by the person rigging the lift, and on a documented periodic schedule by a competent person, commonly quarterly for slings in regular service. The pre-use check is the one that catches most damage: tag, stitching, edges, core.

Unless the manufacturer sets a shelf life, there is no fixed expiry. Retirement is condition based. Cuts, chafe, UV fade, heat glazing, chemical damage or a missing tag end a sling's life whenever they appear, which on hard-working sites can be well inside a year.