Polyester Round Slings

Polyester Round Sling Rigging

When a job calls for lifting slings without the weight and stiffness of wire rope or chain, a polyester round sling is usually the answer. Made in the USA from a continuous loop of polyester yarn wrapped in a durable woven cover, these slings are color-coded by capacity so your crew can identify the right one at a glance, on top of being light enough to store and carry without extra equipment.

Choosing Between Endless and Eye & Eye Styles

Round slings come in two constructions, and picking between them comes down to how you rig and how often you reposition the load rather than how much weight they can handle. Rated capacities, hitch compatibility, and the color-coded jacket system are identical across both styles.

• Endless: one continuous loop with no fixed ends. Because there's no set bearing point, you can rotate where the sling contacts the load on each lift, which spreads out wear and extends usable life.
• Eye & Eye: a wear pad is added at both ends to form a loop eye on each side, which makes for quicker, repeatable rigging when a job uses the same configuration lift after lift.

If you already know which construction fits your job, our dedicated endless round sling and eye and eye round sling pages have the full write-up for each. What follows here covers what's true across both.

Round Sling Specs at a Glance

• Stretch at rated capacity: 3-5%
• Operating temperature range: -40°F (-40°C) to 194°F (90°C)
• Compliance: Meets or exceeds ASME B30.26, WSTDA RS-1, and OSHA standards

Sling Tags and Traceability

Every sling ships with a sewn-in tag covering rated capacity by hitch type, material construction, date of manufacture, and a serial number for traceability, plus the standard industry warning label. The tag itself is a vinyl label sealed in plastic to hold up to jobsite conditions over the sling's working life.

Polyester Sling Capacity Chart: Endless & Eye & Eye

Capacity depends on both sling type and hitch. All round slings work in vertical, choker, and basket hitches, but basket capacity is only at its highest when both legs sit at a 90 degree angle to the load; capacity drops as that angle narrows, and angles under 30 degrees aren't recommended.

Protecting Your Polyester Round Sling (and Meeting Code)

Recognized rigging standards call for protecting any sling that will be in contact with edges, corners, protrusions, or abrasive surfaces, using material strong and thick enough to prevent damage to the load-bearing core, per ASME B30.9. We stock sling protection to cover that requirement, including a cut-resistant option, along with sizing guidance to match protection to the round sling type you're running.

Proof Testing Certificates

A proof testing certificate is available for a small added fee, but it has to be requested before the sling ships, since testing is done on a random sampling basis during manufacturing rather than unit by unit. Certified slings are pull tested at the factory to twice their rated vertical capacity, with the results recorded and available for governing bodies that require it.

Know When to Retire a Sling

Inspect slings regularly and before every use. A few clear signs mean it's time to pull a sling from service, though this isn't a complete list:

• Missing or illegible tag: if you can't read the tag, don't use the sling. Jacket color is not a reliable substitute for the capacity info on the tag.
• Jacket damage: even if the inner load-bearing yarns look fine, damage to the jacket is reason enough to retire the sling.
• Extra knots in the inner yarn: one knot is normal from manufacturing. Any additional knot is a sign of damage.

We're Here to Help

If the standard capacity chart doesn't cover what you need, let us know. Custom polyester round slings can be built up to 100 feet, reach out and we'll get you a quote.

Questions before you order? Call our sales team and we can help you pick the right sling, walk through sizing, or place the order for you directly.

Looking for something beyond standard polyester round slings? We also carry high strength synthetic fiber, chain, and nylon lifting slings, along with high performance round slings for jobs that need a lighter-weight option at similar capacity. Common accessories like shackles and sling protection are available as well.