Will Dunn

October 14, 2020 • 6 min read

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The question often asked to the LES USA team "When Should I Replace My Synthetic Webbing and Round Slings?" is a standard to some and a mystery to others.

In this article we dive in to the types and causes of damage this item can suffer, the required inspection intervals, ways to prevent its early death, and of course, identify the answer to the above - when you need to replace them.

Synthetic Lifting Slings such as webbing and round versions are normally made from 100% polyester or nylon and are manufactured with a 5:1 design factor for use here in the USA.

That by no means should be interpreted to suggest that you can expect this securing strap to take five times the capacity they are rated to. It actually means that they are designed to break at 5 times the working load limit.  The reason for this is to provide added protection for you against accidental operator faults and dynamic overloads.

You should never overload one under any circumstance. Even when you are on the edge of the limit and you don't have a bigger weight limit version at hand. Please put your tools down and buy a bigger one - you can't buy a new body and we always want our valued customers to be safe when using our equipment.

If you've started reading this and are thinking something along the lines of "this is great, but I don't know what this item is", then you can check out the article "web slings, round slings, and synthetic slings - what's the difference?". In this, you get a deeper understanding of what the difference is between all these items and how one can suit you better than the other. 


Webbing and Round Slings, due to their material properties, are more prone to damages through general wear and tear and therefore it is very important to always check for signs of wear and damage (more on this below). 

Damage can occur in a variety of instances from difference sources such as chemical wear and burns from acids or alkali's, cuts and tears from sharp edges and frequent abrasion. Damage also occurs from heat, you should never use webbing or round ones close by or in extreme heat, anything above 194°F (90°C) is too high and you should consider the activities performed close-by such as welding and grinding where spatter could cause damage and burns.

Poorly trained riggers are also known to perform knotting techniques that severely damage the inner cores of round and webbing versions and break those all-important strands of material. A commonly debated factor (and quite a common occurrence for outdoor rigging) is environmental and UV degradation.

Exposure to sunlight as well as dirty and grit-like matter as well as changes in temperature and humidity is known to accelerate the rate at which your synthetic supporting gear will degrade. This rate of deterioration varies according to the levels of exposure to these factors that the goods undergo.

Other factors include the thickness of the material. It is generally recommended that if your using one in outdoor applications, that you remove them from service after 2-4 years. 


All inspections are important and there are three main inspection types; Initial Inspection, Frequent Inspection and Periodic Inspection. 

Upon you receiving a new one or buying one destined for a particular job/activity (such as one from a rental company) it's important that you put the item(s) under an initial inspection to ensure no damage has occurred in transit, no manufacture faults can be noted, and that it is the correct size and capacity for the application.

Frequent Inspection requires that both your synthetic webbing and round versions are inspected prior to each shift or working day in normal applications whilst a frequent inspection should be performed before every lift in more severe applications.

Periodic inspection falls in line with ASME B30.9 or WSTDA WS-1 and requires that a written record is maintained to prove that the item(s) have been inspected periodically by a qualified or designated person and this should be someone who does not commonly perform the frequent inspection.

This should be carried out at a frequency that depends on the service type - if you are using them in a normal environment - yearly. If you are using these goods in a more severe environment then a periodic inspection should be performed more frequently such as monthly or quarterly.

You can get further information on how to look after your goods and the health and safety considerations by checking out a more recent article we put together titled "What are lifting slings and how do you use them?". 


Added protection can be provided to most synthetic types with different weight limits in the form of sleeves, mesh and corner protectors.

Avoiding the following actions will help provide better longevity to your gear and give you better value for money.

  • Dragging them along the floor 
  • Exposure to heat or weld spatter etc.
  • D.I.Y. shortening or connecting methods such as knotting
  • Yanking them from under loads when the load is sitting on top of them
  • Exposing them to chemicals
  • Driving over the item(s) with a forklift or pallet truck (a common occurrence)


There is no precise determining factor or formula available that will predict the life of a synthetic webbing or round version, however, having a good understanding of the product, the effects of applications and environments and taking into consideration the expected service type you will need (normal, severe, outdoor etc.).

As above, if using your gear outdoors then it is recommended every 2-4 years, maybe sooner if additional factors such as salty quayside air exist, for all others one must take into consideration the variables and expected duty of the item in question along with advice from the experts performing the periodic inspections.

Having a knowledgeable supplier and inspection company is crucial to ensuring you get the right type for your application and that is is inspected at a period that not only suffices ASME B30.9, but also prevents accidental failure which would result in death. 

Now that you have an understanding of when to replace these items, you should check out the article "6 ways you can use webbing slings". In this you'll get new ideas on where you can use them, where you can use one, and similar to what we've discussed in this article, important factors to consider before using. 

Will Dunn

October 14, 2020 • 6 min read

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