Everything you need to know about lifting slings
Lif-ting-slings! You’ve seen them around sites all the time, but they’re not very often explained – or at least very well! They’re the given item that just keeps on giving.
Lifting slings are great. And, as the name suggests, they’re used to lift things – usually by running them underneath the thing that needs to be lifted in order to form a sling that can then be hoisted safely and effectively with a crane. Exactly what they’re made of, as well as exactly how they’re used, however, varies greatly.
What are lifting slings used for?
Lifting slings are great for lifting a variety of large, heavy objects that don’t have fastening points themselves. For example, you may need to lift a bunch of metal pipes, a pallet of cement blocks, or any other heavy, awkward object.
Slings usually have an eye on either end to hook onto a crane or other lifting device. Alternatively, ‘roundslings’ can be used. These are conceptually the same but are manufactured to be one continuous loop of material. The roundsling is usually looped over the object and a lifting hook can be hooked through as usual.
How long do lifting slings last?
If properly maintained, lifting slings can last for up to 5 years. However, it’s a legal requirement to inspect them at least every 6 months. These inspections should cover any snags, breakages, frays, or stretched sections to ensure that there aren’t part failures during heavy lifting.
If any potential wear points are spotted, the sling should be replaced immediately in order to avoid potential workplace accidents.
How many different types of lifting slings are there?
There are four common sling materials: nylon, polyester, wire rope, and chain. These are all intended to meet different needs which the different materials cater for. However, slings are always sold to meet length and weight requirements. So you should always ensure that the sling you’re using is appropriate for the job.Nylon Slings
Nylon slings are great for jobs where flex in the sling is required. They’re lightweight (thus increasing the actual liftable load of the crane) while remaining strong. As they’re able to stretch by 6-8% of their nominal length, they’re especially useful for things such as liquid or brittle loads. That said, if liquid loads aren’t properly contained and nylon gets wet, it can absorb the liquid and become brittle.Polyester
Similar to nylon, polyester slings are able to stretch a little (though less than nylon, at 3% of nominal length) but have the added benefit of being safe to handle open liquids, as well as work in areas with acids and bleach agents present.
They’re often known as web slings or rigging slings because of the webbed composition. Additionally, polyester slings are great where surface marking of the material is to be avoided – such as hoisting boats.Wire Rope
Wire rope is rope-shaped but comprised of wire strands. In the same way a natural rope will have fibre strands twisted around each other to make the larger rope, a wire rope has wires twisted around a core to make a thicker, sturdier, rope.
Wire ropes are categorised by the number of strands around the core and, perhaps counter-intuitively, the more strands a rope has, the greater its flexibility. This is because it resists kinks due to the higher tensile strength at any one point.Chain
Chain slings tend to be constructed of high grade steel alloy and are used for the most demanding lifting applications. They have the benefit of being able to be adjusted and fitted for any lifting assembly but care has to be taken to avoid rust and corrosion.
How do you properly sling a load?
There are numerous ways to properly sling loads depending on the size, shape, density, and centre of gravity of what needs to be lifted. Proper attention must be given to the type of hitch (if at all) used for the sling too. A ‘choker hitch’ (one where the sling hooks through itself), for example, should only be used to lift a max of 75% of its nominal lifting capacity.
The most important thing to keep in mind is that the load should be properly secured, and the lifting point should be directly above the centre of gravity of the load. This ensures that the load doesn’t tip during lifting.
What should you look for when inspecting slings?
As mentioned above, slings must legally be inspected at least every six months for defects, signs of damage, frays, kinks. However, an inspection on each use is a sensible best-practice to avoid any accidents.
Official sling inspections should be carried out by a trained person but some other things to look out for are worn (or missing) identification marks, acid burns, worn fittings, and melting or discoloration of any part of the sling.
If you’re looking for great quality slings in any size, check out our catalogue.