How to Inspect and Prevent Nylon Sling Damage

No matter how durable your nylon web sling is, eventually it will wear out and need to be replaced. From cuts and abrasions, to chemical and heat damage, there are several factors that can lead to a damaged sling. Inspecting a web lifting sling for damage before each use protects the load you are lifting and the people working on the job site.

ASME B30.9 standards dictate that a synthetic web sling shall be removed from service if conditions such as the following are present on the sling:

• Missing or illegible sling identification.
• Acid or caustic burns.
• Melting or charring of any part of the sling.
• Holes, tears, cuts, or snags.
• Broken or worn stitching in load bearing splices.
• Excessive abrasive wear.
• Knots in any part of the sling.
• Discoloration and brittle or stiff areas on any part of the sling, which may mean chemical or ultraviolet/sunlight damage.
• Fittings that are pitted, corroded, cracked, bent, twisted, gouged, or broken.
• For hooks, removal criteria as stated in ASME B30.10
• Other conditions, including visible damage, that cause doubt as to the continued use of the sling.

Nylon Sling Inspection Checklist

Surface and Edge Cuts

Inspection: When there is a significant number of broken fibers, the sling should be taken out of service. Remember all of the individual fibers in a web sling contribute to the overall strength. If there are broken fibers of equal length, that indicates that the sling has been cut by an edge. Red core warning yarns may or may not be visible with cuts and are not required to show before removing slings from service.

Prevention: Always protect synthetic slings from being cut by corners and edges by using wear pads or other devices.

Holes, Snags, and Pulls

Inspection: Punctures or areas where fibers stand out from the rest of the sling surface.

Prevention: Avoid sling contact with protrusions, both during lifts and while transporting or storing.

Abrasion

Inspection: Areas of the sling that look and feel fuzzy indicate that the fibers have been broken by being subject to contact and movement against a rough surface. Affected areas are usually stained.

Prevention: Never drag slings along the ground or pull slings from under loads that are resting on the sling. Use wear pads between slings and rough surface loads.

Heat and Chemical

Inspection: Melted or charred fibers anywhere along the sling. Heat and chemical damage can look similar and they both have the effect of damaging sling fibers and compromising the sling's strength. Look for discoloration and/or fibers that have been fused together and often feel hard or crunchy.

Prevention: Never use nylon or polyester slings where they can be exposed to temperatures in excess of 200° F. Never use nylon or polyester slings in or around chemicals without confirming that the sling material is compatible with the chemicals being used.

Knots

Inspection: Never use a sling with a knot. Knots compromise the strength of all slings by not allowing all fibers to contribute to the lift as designed. Knots may reduce sling strength by up to 50%.

Prevention: Never tie knots in slings.

Broken/Worn Stitching

Inspection: Stitch patterns in web slings have been engineered to produce the most strength out of the webbing. If the stitching is not fully intact, the strength of the sling may be affected. Discontinue a sling if you find loose or broken threads in the main stitch patterns.

Prevention: Never pull slings from beneath loads where stitch patterns can get hung up or snagged. Never overload the slings or allow the load edge to directly contact the stitch pattern while lifting. Never place a sling eye over a hook or other attachment whose width/diameter exceeds 1/3 the eye length.

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