NFPA 1983 elongation standard specifies elongation measured at 10% of breaking strength. What is the maximum elongation?

• A. 12%
• B. 8%
• C. 9%
• D. 10%

Answer: (D)

Rope elongation specifications focus on how much a rope stretches under a standardized light load. In NFPA 1983, elongation is measured when the rope is loaded to 10% of its breaking strength, and the standard sets a maximum allowable elongation at that point. The maximum is 10%, meaning the rope may stretch no more than 10% of its original length under that test load. This keeps rope behavior predictable and safe for life-safety use. Elongation is a percentage of the original length, not a percentage of breaking strength. So 10% is the limit the standard allows; values like 8% or 9% would be stricter than required, and 12% would exceed the limit.