Polyester Round Slings 101: The Guide for Safe, Versatile Lifting
When you’re lifting delicate or irregularly shaped loads, you need a sling that offers strength and pliability. Polyester round slings are versatile, convenient, and cost-effective tools for lifting and rigging applications. At US Cargo Control, we have over 100 polyester sling options in stock and ready to ship.
What is a Polyester Round Sling?
A polyester round sling is a loop of polyester yarn covered in a protective polyester jacket. This design distributes weight evenly to minimize stress points and damage risk to the load.
These slings are typically color-coded by capacity (up to Type 7 - Blue), equipped with clear identification tags detailing capacities, and valued for their strength, flexibility, and usability in applications where headroom, load surface protection, and load shape are concerns.
Types of Polyester Round Slings
There are two types of polyester round slings:
Endless Polyester Round Slings: A continuous loop design with no ends. Wear points can be adjusted with each use, extending the life of the sling. They are incredibly versatile, making them the most popular option.
Eye & Eye Polyester Round Slings: A polyester round sling with loops (“eyes”) sewn on each end of the sling, allowing it to be easily attached to hooks or shackles. These are best for use cases when a more secure connection to the load is needed.
Both types of polyester round slings have identical rated capacities and compatibilities with all sling formations.
Benefits of Polyester Round Slings
Why choose a polyester round sling over another sling option? Look at both the advantages & disadvantages to determine if it’s the right sling for your application.
Flexibility & Pliability
The pliable design of a round sling allows it to easily contour to the shape of a load better than other types of slings.
Reduced Stretch Capacity
Polyester round slings have less elongation (3 – 5% at rated capacity) than nylon slings, making them a better choice for low-headroom lifts. This also prevents polyester round slings from locking up when used in a choker hitch.
Durability
Polyester slings are mildew-resistant and will not absorb water, making them an excellent choice for outdoor and marine applications. Because they have protective jackets surrounding the load-bearing core, oil, grease, dirt, debris, and UV rays will not degrade the load-bearing core. This also protects your load from scratches and abrasion more than wire rope or chain slings.
However, polyester round slings are more susceptible to damage and may need more frequent replacement than wire rope or chain slings. They are more cost-effective than wire rope and chain slings, though.
Polyester Round Slings vs. Other Materials
Material |
Key Advantages |
Use Cases |
| Flexible, affordable, low stretch | General lifting, low headroom, delicate loads | |
| More stretch, handles exposure to sulfuric acid & alkalis | General lifting, irregularly shaped loads | |
| Stronger, lighter, less elongation | Heaviest loads; extreme environments | |
| Highest durability, high temp rated | Rigging, construction, foundries | |
|
Strong, high temp rated, abrasion resistant |
Harsh environments, industrial loads |
Polyester Slings vs. Nylon Slings
Polyester slings are very similar to nylon slings but only stretch 3-5% at rated capacity, making them a better choice for low-headroom applications. They also differ in the types of chemicals they can safely be exposed to, as polyester is impervious to bleaching agents and acids, but cannot handle sulfuric acids or alkaline.
Polyester has the same upper temperature limit as nylon.
Polyester Slings vs. HMPE Slings
High Performance Round Slings (HMPE) are smaller, lighter, and stronger than polyester round slings. They also have 75% less elongation and are more impervious to environmental conditions.
However, HMPE round slings are generally more expensive than polyester slings.
Polyester Slings vs. Chain Slings
Chain slings are more durable and stronger than polyester round slings. They are preferred in high-temperature applications or for heavy-duty loads.
Polyester slings are lighter and more cost-effective than chain slings.
Polyester Slings vs. Wire Rope
Polyester slings are more flexible and easier to use than wire rope slings. But wire rope provides superior strength and resistance to high temperatures. Wire rope is used more in harsh environments with heavy-duty loads.
Key Features of Polyester Round Slings
Color Coded Jacket System
Polyester round slings are generally manufactured with a color-coded fabric jacket based on the weight capacity of the sling. Note: Our slings are color-coded up to Type 7 (blue - 21,200 lbs.). All slings Type 8 and above will be orange or brown. Always confirm capacity using identification tags.
Stretch Capacity
The polyester round slings stretch at 3-5% at rated capacity. This is less stretch than a nylon lifting sling, which prevents polyester slings from locking up on the load when used in a choker hitch.
Chemical Resistance
Polyester round slings are not affected by bleaching agents or common acids. However, they can be damaged by sulfuric acid or alkaline.
Temperature Limits
Polyester round slings should not be used in temperatures over 194 degrees Fahrenheit (90 degrees Celsius) or under -40 degrees Fahrenheit (-40 degrees Celsius).
How to Measure Polyester Round Slings
A polyester round sling is measured from sling tip to tip when laid in a flat position. It should NOT be measured by circumference.
Also, note that the diameter of a polyester round sling refers to the diameter of the polyester rope core, not including the fabric jacket.
Polyester Round Sling Protection
Per ASME B30.9 (2021) 9-5.10.4(d), "slings in contact with edges, corners, protrusions, or abrasive surfaces shall be protected with a material of sufficient strength, thickness, and construction to prevent damage."
Ensure your lifting setup meets the requirements - explore our selection of sling protection, including a cut-resistant option! If you're unsure what you need, we have several charts that break down which sling protection sizes work with each polyester round sling type.
When to Replace a Polyester Round Sling
Replacing a polyester round sling at the right time keeps your lifts safe and secure. If you notice any visible damage – cuts or tears in the jacket, debris stuck in the jacket fibers, or the jacket becoming threadbare – you should remove the sling from use.
To check for internal damage of the core, feel around the sling. The internal polyester threads will be tied together with one knot inside the jacket that you’ll be able to feel. If you notice more than one “knot,” or any irregularities with the core, replace the sling immediately.
Polyester Round Sling Safety and Compliance
All US Cargo Control’s polyester round slings meet or exceed all ASME B30.26, WSTDA RS-1, and OSHA requirements.
Custom Polyester Round Slings
Looking for a specific size of polyester lifting sling, but don’t see it on our site? Let us know. Custom lifting slings are always an option at US Cargo Control.
Sling Proof Testing Certificates
Proof testing certificates are available for a nominal fee and must be requested at the time of order. Testing is performed in the factory where the polyester round sling is pull-tested to 2x the vertical rating and officially recorded as proof for governing bodies.
Since only random slings are tested during production, a request must be made before manufacturing.
We're Here to Help
Have questions? Call our lifting experts today at 1-866-444-9990 or email us at customerservice@uscargocontrol.com. One of our team members will be happy to help - we can even place your polyester round sling order for you.
Other styles of slings are also available, including plasma, chain, nylon, and high-performance round slings.
