Effects of
Wear & Abuse
Far too many web slings have been discarded prematurely simply because abusive and careless work habits caused irreparable damage. Following are examples of damage typically caused by abuse and misuse. Regardless of whether a sling shows damage from abuse or normal wear, the overriding rule is in all cases is that sling eyes should be cut and the sling discarded immediately whenever damage is detected.
TENSILE BREAK - Characterized by a frayed appearance at the point of failure or damage. Such damage is caused by loading the sling beyond its existing strength. The example pictures was pulled to destruction on a testing machine.
CUTS - A cut is easily identified by a clean break in the webbing structure or fibers, and usually results from the sling contacting a sharp object or unprotected edge of a body or eyes of a web sling. Red Guard warning yarns are woven into webbing of many slings to provide a warning when a serious cut has occurred. Cuts from contact with sharp corners during lifts can often be avoided by using wear pads on the sling for protection of the fabric.
CUT AND TENSILE DAMAGE - The sample shown illustrates a typical shop failure in which a sling is used after having received a cut by a sharp object along one edge of the sling body. The cut severely reduces lifting capacity, and continued usage will result in the sling breaking much as shown. Such a failure often occurs at a level far below the Rated Capacity of the sling.
ABRASION DAMAGE - The most common abrasion damage occurs either when a sling slips while in contact with a load during a lift, or when being pulled from under a load. Abrasion is characterized by frayed fibers on the surface which exposes the "picks," or cross fibers, of the webbing that hold in place the load-bearing (lengthwise) fibers. Further abrasion at this point will expose the Red Guard warning yarns to signal the inspector or sling user that serious damage - and loss of lifting capacity - has occurred. Any damage to load-bearing fibers should be viewed seriously.
ACID DAMAGE - Although polyester webbing has considerable resistance to certain acids, any contact with strong acids should be avoided. Nylon should never be exposed to any acid. Metal fittings on slings should not be exposed to any acid or corrosive liquid.
Example A - The damage show to this nylon webbing occurred when sulfuric acid (such as used in an automobile batter) was heated to 100 degrees C (212 F) and dropped on the webbing. The charring of surface fibers seen here is typical of acid damage. The deterioration shown will coninue over time and severely affect webbing strength.
Example B - A piece of Nylon webbing was immersed in sulfuric acid at room temperature for three weeks, resulting in the significant damage shown. Note that fibers are softened and swollen, and the entire fabric is grossly distorted, virtually destroying the webbing. Precautions should be taken to never store slings where they may be exposed to acide fumes (which can be as destructive as liquid) or to possible contact with liquid.