One of the most important features of quality rigging hardware is the ability to stretch when overloaded. This ductility is a design feature and warning that your rigging is about to fail.

Permanent stretch starts at around 3-4 times the Rated Capacity and indicates a very serious ‘overload’ situation and at that point, many other parts of your rigging will be at high risk of failing as well. Some signs are locked shackles pins, stretched hooks and links, stiffened chain, attachments that will not rotate or articulate, etc.

All Rigging Standards specify that products shall have “sufficient ductility to permanently deform before losing the ability to support the load”.  Ensure your rigging complies to this important requirement.

https://www.unirope.com/inspection-testing/general-proof-testing/