Once saw a crane taking 22 ton with a 3 ton span set ......Serious slings in fairness.... The rigger on that job was fired as the crane driver didn't know what sling was on his hook as it was a blind lift.
In the real use the Rounslings often are bended around edges with a smaller Radius as the Reglements allowed. After a load with max. Capacity the Slings get used again for other loadings. Im echten Einsatz werden die Rundschlingen oft um Kanten mit geringem Radius gelegt. Die Schlingen werden auch mehrmals verwendet auch wenn sie an ihrer Belastungsgrenze waren.
Just used some cheap Amazon choker slings and they were incredible. We put 40k on a 3T sling and did it repeatedly without it breaking, it took nearly 60k to break it and even the 40k didn't stretch it. Seems a waste of money to buy slings that cost nearly 10x as much.
This is an advertisement for steel shackles and synthetic fiber slings made by Spanset. The machine gradually applies an increasing load up to either a prescribed limit or to a breaking point. The results are then used to certify a load rating, to study failure modes, and improve product design.