"To provide some detailed analysis of the strength rétention of used slings, and to give the dealers a background on the safety of used slings in the field, we have undertaken this study. The comfort level a dealer may feel after reading this report should not reduce or eliminate the dealer's efforts to have customers return slings for repair évaluation. When indicators (cover, Fiber Optie, Tell-tails) show the sling should be removed from service, the customer must be trained to take appropriate action.
In laboratory conditions, two distinctive test programs have shown that new K-Spec™ high performance fiber used in the construction of Twin-Path® Extra slings shows no détérioration from fiber on fiber abrasion or fatigue.
The first test program was conducted in 1997 at the laboratories of Tension Member Technology in Huntington Beach, CA. This test exposed both Kevlar® and K-Spec™ fiber to a cyclic-tension-testing program consisting of pulling each sling 50,000 times to a 50% overload and then performing a ***break test*** on the designated slings." (see:
http://www.slingmax.com/)
The translation workplace 
