Polyester Slings vs Nylon Slings: Which Web Sling Type is Better?

Are polyester lifting slings better than nylon lifting slings? This is a question our lifting and rigging product experts commonly get and the answer, as it often is with rigging gear, is that it depends on the job at hand.

Before we dive into the key differences between nylon slings and polyester slings, there are many similar advantages to these two types of synthetic slings that are important to know.

Advantages of Synthetic Webbing

1. Ideal for delicate loads

One of the most common reasons for a rigger to use synthetic slings instead of wire rope slings or chain slings is th fact that they won’t scratch or crush your load. That’s why synthetic slings are extremely popular in the construction industry and with ship haulers.

2. Cost-efficient

Synthetic slings are also an attractive choice due to their lower cost. If you’re wondering whether nylon slings are cheaper than polyester slings, don’t. The prices are more or less the same, and your focus should be on choosing the right sling for the job.

3. Lightweight

Compared to wire rope and chain, synthetic slings are much lighter, making them easier to transport and handle. Again, nylon is typically a little heavier than polyester, but it’s not much of a difference when you consider the weight of chain and wire rope.

4. Strong

It’s true that nylon is stronger on an individual fiber level, but a polyester sling can be made just as strong as a nylon one by adding more threading. And both types can easily lift several thousand pounds. So while it’s important to use a lifting sling that’s rated for the load your lifting, this won’t affect your choice between nylon and polyester.

Physical Differences

Now that you know how they’re similar, let’s look at the differences between the physical characteristics of nylon and polyester to determine which material type is best for your job.

Nylon has more stretch

This is one the most important differences between nylon slings and polyester slings. While nylon slings have more give to them (about 7 to 10 percent stretch when at WLL) that does not mean they are weaker than polyester (typically 2 to 3 percent stretch at WLL). The main reasons you would want more or less stretch when lifting a load include overheight lifting room and the potential for “snapback”.

If you have height limitations, polyester is probably the better choice. If your load could bounce around a lot, the extra stretch of nylon will reduce the danger of the strap snapping back at you or others. This difference in the stretch is why you typically see recovery straps made of nylon and tow straps made of polyester.

Polyester is softer and more flexible

Both nylon and polyester slings are good for delicate loads, but if you’re wondering which one is best for the most delicate loads, it’s polyester. The chemical coating on nylon webbing gives it a slightly more coarse texture.

Polyester is also a bit more flexible than nylon. By flexible, I’m not talking about stretch but rather the ability to wrap tightly around a load and grip the most surface area.

This is an important difference, especially when choosing between nylon endless slings and polyester endless slings.

nylon round endless lifting sling
Nylon Endless Sling
polyester round endless sling
Polyester Endless Sling

Environmental Differences

Another key question to ask when choosing between nylon slings and polyester slings is, what are the environmental conditions? There’s a reason why ship haulers and those in marine environments prefer polyester slings, they absorb less water and are just a bit more resistant to UV rays. But, you also need to consider the differences when it comes to chemical resistance.

Nylon slings can’t resist acids or bleaches

Avoid using nylon slings if you’re operating anywhere near sulfuric, nitric, hydrochloric, or phosphoric acids. Nylon is also unresistant to oxidizing bleach agents such as sodium hypochlorite, hydrogen peroxide, sodium percarbonate, and calcium hypochlorite.

Polyester slings can’t resist ethers or alkalis

On the other hand, polyesters Achilles heel is ethers and alkalis. Among other chemicals, this includes diethyl ether, dimethyl ether, sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium carbonate, and magnesium hydroxide.

Polyester Slings

best eye to eye lifting sling

browse all polyester sling

Conclusion

In short, synthetic lifting slings are a great choice due to their ability to handle delicate loads, lower cost, lightness, and impressive strength. In the polyester sling vs nylon sling matchup, the winner is whichever one meets the demands of your specific job best.

Nylon slings have more stretch but can’t be used near acids or bleaches. Polyester slings are softer and hug to load surfaces better but can’t be used near ethers or alkalis.

If you have any additional questions about nylon slings or polyester slings, give our rigging product experts a call at 800-404-7068.

How to Choose a Lifting Sling

Choosing the right sling for lighting can be confusing, but it’s important to take the environment and conditions where the lifting sling will be used into consideration.

Nylon lifting sling

image of nylon lifting sling from US Cargo Control

Nylon lifting slings are a popular choice because of their multi-purpose uses. A nylon web sling is unaffected by petroleum products like grease and oil. Nylon slings are also resilient to specific chemicals including ethers, strong alkalies and aldehydes. Nylon webbing is not a good choice for uses involving bleaching agents or acids, or for use in temperatures over 194 degrees Fahrenheit (90 degrees Celsius). Nylon also stretches at approximately 8-10%, so it should not be used when elongation is not intended.

 

Polyester lifting sling

Polyester Round Eye & Eye Lifting Sling

Like a nylon lifting straps, polyester round slings also have temperature guidelines, and are not advised for use in temperatures over 194 degrees Fahrenheit (90 degrees Celsius). Unlike nylon, they will stretch only approximately 3% of its rated capacity. A polyester round sling can handle acidic environments because the fabric is not affected by bleaching agents or common acids. Polyester webbing, however, should not be used if it will come in contact with sulfuric acids or alkaline.

 

Chain lifting sling

Image of Double Leg Chain Sling from US Cargo Control

Chain lifting slings are ideal for rugged environments and jobs. They resist abrasions, cutting and can maintain their strength and integrity even in extremely high temperatures up to 400 degrees Fahrenheit (204 degree Celsius). Chain slings are generally constructed in Grade 80 steel, but a Grade 100 chain is usually available on request. Grade 100 chain offers more strength (about 25% more) for lifting chains, yet weighs less than traditional Grade 80 lift chains. Another benefit of a chain sling is its ability to be customized for almost any type of lift. However, a chain hoist can be expensive and the prices can vary due to the market fluctuations.

 

Wire rope lifting sling

image of Wire Rope Lifting Sling from US Cargo Control

Wire rope slings are similar to a chain sling in that it offers excellent durability, strength and resistance to high temperatures. Wire rope, however, is more cost-efficient than chain so it’s a great choice is price is a concern. Because abrasion-resistance and flexibility of the wire rope can change depending on its configuration, a chain sling can be manufactured using a specific type of wire rope. Typically, wire rope is made from either 6×19 or 6×37 classes of rope. A 6×19 is the most widely used because of its ideal combination of flexibility and abrasion resistance. A 6×37 class rope is more flexible, but offers less resistance to abrasion.

 

Other factors will go into determining which lifting sling type is best for your specific job, such as the item(s) being lifted, capacities needed, etc. For help choosing a lift sling, call our product specialists at 800-660-3585. They’ll be happy to any answer questions you may have.