In industrial overhead crane incidents, poor rigging practices are the most common cause of load drop accidents, resulting in severe injuries and fatalities. To keep your employees, clients, and bystanders safe and avoid hefty fines, you need to educate everyone on their equipment.
Learn about the types of chain sling assemblies for hoisting and lifting applications below.
There are numerous configurations of chain sling assembly types. They’re divided into four main types:
Generally, the more legs or chains an assembly has, the greater its weight capacity. The four main types are further divided into many other configurations, each with different parts. The assembly is then referred to with letters that correspond to them to form an acronym:
Instead of memorizing each configuration, the best way to understand a chain sling assembly is to learn about the individual parts.
An assembly has anywhere from 1 to 4 legs attached to the collector ring, each with its own lower-end fitting. Instead of a collector ring, single-leg chain slings can have a hook as an upper-end fitting. The letters assigned to the number of sling legs are as follows:
Chain sling assemblies have an upper-end fitting at the top, usually a collector ring. It’s also called a collector link, master link, or master ring. This connects all the sling legs to the crane hook or other part of a rigging assembly. The types of connector rings and their corresponding letter include:
Oblong links are the most common type of collector rings used and are ideal for attaching to crane hooks with a large hook saddle measurement.
Pear-shaped links can only accommodate small sling assemblies with 1 to 2 hooks. However, their shape makes them ideal for attaching to narrow hooks.
Round master links are rarely used. Its shape makes it less ideal for connecting to large, deep crane hooks like oblong links. In most applications where a round master link is used, an oblong link can be used instead.
Triple and quadruple-leg chain slings may also have master link sub-assemblies. These consist of two coupling links attached to the collector ring. This allows the sling legs to be split between the sub-assemblies.
While attaching 3 to 4 legs to the single collector ring is possible, it would have to be thicker and heavier, making it difficult to manage. Sub-assemblies allow for the use of a smaller collector ring.
At the bottom of the assembly, a lower-end fitting is attached to the end of each chain sling leg. These are usually hooks, allowing the chain assembly to lift objects. Some of the commonly used types and their corresponding letter include:
As mentioned before, single-leg chain slings may also have a hook as the upper-end fitting. This means you may see the letters listed above as the 2nd letter in those types of assemblies.
Each type of hook serves a different purpose. Grab hooks have a narrow throat. They’re used to shorten or hold a chain in tie-down applications and load-rated lifting slings.
On the other hand, foundry hooks have a deep, wide throat. As their name suggests, they are used in foundry work, and their design allows them to fit trunnions and handles on molds or castings.
Some chain sling assemblies have adjusters. These are optional add-on hooks that allow you to shorten the sling legs. You may want to do this so that the weight is evenly distributed and there’s no excessive load on any one sling leg.
If the acronym denoting the chain sling assembly’s configuration has a fourth letter, this indicates the presence of an adjuster and its position:
The American Society of Mechanical Engineers (ASME) requires chain sling assemblies to have a permanently affixed tag. This provides the following information regarding the sling:
Alloy chain sling tags must also provide:
These are just the minimum requirements for the tags. They may also include information such as safety measurements.
Now that you understand what the letters stand for, here are some chain sling configuration examples to further illustrate:
Guarantee the quality of your 4-leg lifting chain slings by getting them from Southeast Rigging. Choose from our wide range of grade 8 and grade 10 steel slings to maximize your operations’ safety. You can also have them custom-engineered to fit your needs.Discuss your project with our team by filling out our contact form.