An exact determination of when to retire a sling depends on many variables, and limited federal guidelines exist. Rather sling retirement (and safety factors) must be left to the judgement of a trained and experienced professional who is capable of evaluating remaining strength in the sling. Proper allowance must be made for deterioration as disclosed by inspection. The safety of an operating sling depends upon this remaining strength. The following conditions must be taken into account when determining the safe operating condition of a sling.
For strand laid and single part slings, ten randomly distributed wires on one rope lay,or five broken wires in one strand in one rope lay.
For cable laid and braided slings of less than eight parts, twenty randomly distributed broken wires in one lay or braid, or one broken strand per sling.
For braided slings of eight parts or more, forty randomly distributed wires in one lay or two broken strands per sling.
Severe localized abrasion or scraping.
Kinking, crushing,bird caging or any other damage resulting in distortion of the wire rope.
Evidence of heat damage: if a wire rope sling having a fiber core is exposed to temperatures in excess of 200 degrees ; or if a wire rope sling having an IWRC is used at temperatures above 400 degrees or below -60 degrees.
End attachments that are cracked, deformed or worn.
Hooks that have been opened more than 15% of the normal throat opening measured at the narrowest point more than10 degrees from the plane of the unbent hook. 9.) Corrosion of the rope or end attachments.
Recommended Operating Practices:
Destroy retired slings
Never expose slings to temperatures in excess of the manufacturer’s recommendations.
Use a sling that is long enough to provide the minimum practical vertical angle.
Never shorten a sling with knots,bolts or other methods.
Never twist or kink the legs of a sling.
Never load a sling in excess of its rated capacity.
Center the load in the base (bowl) of the hook to prevent point loading.
When using a basket hitch, balance the load to prevent slippage.
Always protect slings from sharp edges.
Securely hitch each sling to its load.
Never pull a sling from under a load while that load is resting on the sling.
Never use homemade fittings and attachments.
Never make a sling from used wire rope.
Never use any sling that is of questionable strength and condition.
Never use a sling unless it has a manufacturer’s identification tag on it with the safe working load limit, diameter, length, cert number and original manufacturers' date.