Read on to learn the difference between chain sling wear and stretch, from our guest bloggers CM.
Chain Sling Wear & Stretch: what’s the difference?
Frédéric, a mechanical engineer who works for a Canadian public utility company, in the auxiliary equipment department asks CM:
“You said a sling should be removed from service if it stretches. But, you also said that 10% of wear is permissible. Does this mean that a stretch of 5 to 10% should be ok, because wear will make the sling stretch (the reach will increase)?”
Henry Brozyna, CMCO trainer & safety webinar presenter answers:
Chain sling wear and stretch are two different things and both will make the sling length increase. So, it is sometimes difficult to differentiate between the two.
Wear will show itself at the bearing points of the links and can exhibit itself in the bearing points of the chain as a groove. A certain amount of wear is permissible and that will happen over time. Check with the manufacturer to see how much wear they allow.
Stretch or elongation are clear signs of overloading. As such, ASME B30.9 Slings lists stretched chain links or components as one of the reasons a chain sling shall be removed from service. The word “shall” in a standard resolves any doubt. No stretch or elongation is allowable.
CM Chain Sling Inspection Webinar
Read the original article here via CM Works Blog