A chain should be replaced when its length becomes __________ longer than the original length.

• A. 3%
• B. 5%
• C. 1%
• D. 2%

Answer: (A)

Chains stretch as they wear under load, and that elongation changes how the chain engages with fittings and distributes force. A practical threshold for replacement is when the chain length has increased by three percent compared with its original length. Reaching this level shows enough wear that the chain’s strength and fit are compromised, raising the risk of failure or unsafe operation under load. Smaller increases (like one or two percent) don’t give enough margin, while larger increases (such as five percent) would allow proceeding with a chain that’s already noticeably degraded. To apply this, measure a defined length of the chain and compare it to the original; if it’s about three percent longer, replace it.