Polyester Round Sling Strength Test: USCC vs. Competitor
Watch the video below to see what happens when we put our US Cargo Control type 7 polyester round sling head-to-head against a competitor’s sling in a break strength showdown.
Not All Slings Are Built the Same
When you’re lifting heavy loads, you must trust your gear. Polyester round slings are a top choice for overhead lifting professionals because of their strength, flexibility, and durability. But not all slings are created equal, even if they have the same working load limit (WLL).
To find out how our gear stacks up, we tested a USCC sling against a lower-cost competitor version. Both were rated as type 7 endless polyester round slings with the same vertical working load limit (21,200 lbs.), and both were supposed to deliver the same performance.
What we discovered might make you rethink your lifting equipment.
Breaking Down the Numbers
To understand the significance of the test, it’s important to know the relationship between a sling’s working load limit and break strength.
The working load limit is the maximum weight a sling is rated to lift in normal conditions. The break strength is the point at which the sling physically fails. It will always be higher than the working load limit, by a factor called the safety factor. Both slings in the test had a safety factor of 5:1, which means their break strength should reach at least 106,000 lbs.
To learn more about working load limit, break strength, and safety factor, check out this blog.
Real-World Testing on the USCC Test Bed
Our manufacturing team in Urbana proof-tests equipment with our in-house test bed to ensure it meets or exceeds necessary standards for safe usage. Our team can proof-test products on request – if you are interested in a proof-test, contact our team for more information.
The test bed applies steady tension to pull the sling (or other equipment) to the desired breaking strengths, up to 150,000 lbs.
The Results
Using our in-house test bed, we pulled both slings to failure under steadily applied tension, mimicking the kind of load stress slings face during actual lifts.
The competitor’s sling failed at 129,400 lbs. Ours held on until 142,700 lbs.
That’s a 13,300 lb. difference – more than 10% higher – proving our sling delivers a significantly greater safety margin. Just as importantly, our sling failed in the expected pattern, confirming that it is built to meet consistent and reliable manufacturing standards.
What This Means on the Job Site
Even though you should never lift above your gear’s WLL, much less lift close to its break strength, that added strength and safety margin matters. It provides a cushion of confidence on the job, especially nice to have in unpredictable or harsh lifting conditions. A stronger sling doesn’t just last longer – it also behaves more reliably under pressure. That means fewer risks and more control.
The USCC Difference
US Cargo Control slings are made and quality-tested by a team that understands the stakes. When you use a USCC sling, you can trust that you’re getting proven performance, dependability, and the safety that you deserve.
So, if you’re wondering whether all polyester round slings are made the same, this test should give you the answer.
Check out our selection of high-quality polyester round slings, as well as our full catalog of lifting slings and rigging hardware.
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