Which test is a nondestructive method where a sling is subjected to a tension force greater than its rated load but less than its breaking strength?

• A. Proof test
• B. Hydrostatic test
• C. Destructive test
• D. Static test

Answer: (B)

Understanding how to verify a sling’s strength without causing damage is done through a proof test: you apply a tension higher than the rated load but below the sling’s breaking strength. The purpose is to confirm the sling can handle more than what it’s normally loaded to in day-to-day use, while still staying within its safe limits. Because the load never reaches the point where the material would fail, the test is nondestructive—you inspect the sling afterward for any signs of damage, wear, or deformation but you don’t break it.

Hydrostatic testing, by contrast, uses fluid pressure to test containment and strength of hoses, pipes, or other pressure vessels. It isn’t about applying tensile load to test the sling’s ability to carry weight, so it isn’t the right fit for this scenario. A destructive test would deliberately damage the item to study failure modes, which isn’t appropriate when the goal is to preserve the sling. A static test is a general term for applying load without dynamic shock, but it doesn’t specify exceeding the rated capacity in the way a proof test does.