At what level of wear should a lifting sling be discarded?

Knowing when to discard a lifting sling is critical for workplace safety—using a worn sling can lead to catastrophic failures, injuries, or damage to goods. Lifting slings, whether made of polyester, nylon, or other materials, undergo wear and tear with use, and recognizing the warning signs of excessive wear is key to preventing accidents. So, at what level of wear should a lifting sling be discarded? Let’s break down the key indicators, and why choosing a durable brand like ChengHua can extend the lifespan of your slings.

First, fiber damage is a major red flag. For synthetic slings (the most common type), look for broken or cut fibers. If more than 10% of the fibers in any section are broken—especially in the load-bearing areas— the sling should be discarded. Even a small number of broken fibers can weaken the sling’s overall strength, as the remaining fibers must bear more weight. Fraying along the edges is also a concern, as it indicates the sling is starting to unravel, which will only worsen with use.

Abrasion is another common issue. If the sling shows significant thinning or has a “fuzzy” appearance due to friction against rough surfaces (like metal or concrete), it’s time to replace it. Pay special attention to the areas where the sling comes into contact with hooks, loads, or other equipment—these are high-wear zones. If the abrasion has worn through more than 10% of the sling’s thickness, discard it immediately.

Cuts or tears, even small ones, are dangerous. A cut that penetrates more than 10% of the sling’s width weakens its structure, as it creates a point where the sling can split under load. This is especially true for flat slings, where a tear can spread quickly during lifting. Never attempt to repair a cut or tear with tape or stitching—this does not restore the sling’s original strength.

Heat or chemical damage is another indicator. Exposure to high temperatures (from welding sparks, for example) can melt or harden synthetic fibers, making them brittle and prone to breaking. Discoloration (such as darkening or charring) is a sign of heat damage. Similarly, contact with chemicals (acids, oils, or solvents) can degrade materials—look for swelling, shrinking, or a sticky texture, which mean the fibers have been compromised.

Distortion or deformation is also a problem. If the sling’s eyes (the loops where hooks attach) are stretched, misshapen, or have pulled away from the stitching, the sling can no longer distribute load evenly. This uneven distribution increases stress on certain areas, leading to failure. Similarly, if the sling has permanent knots or kinks that can’t be straightened, it’s unsafe to use.

ChengHua’s lifting slings are designed to resist wear, thanks to high-quality materials and protective features. Their slings use thick, high-tenacity fibers that are more resistant to cutting and abrasion, and many models include wear pads in high-risk areas to extend lifespan. However, even with these features, regular inspection is essential. ChengHua recommends inspecting slings before each use and keeping a log to track wear over time.

It’s important to note that no matter how durable the sling, all slings have a lifespan. ChengHua’s slings are built to last longer than generic brands, but they still require careful monitoring. If any of the above wear indicators are present, err on the side of caution and discard the sling.

In summary, discard a lifting sling if it has more than 10% broken fibers, significant abrasion, cuts/tears over 10% of width, heat/chemical damage, or distortion. By following these guidelines and choosing durable slings from ChengHua, you can ensure safe lifting operations and avoid the risks of using worn equipment.