What is the rule of thumb for the length increase of a steel chain per additional 3 lbs of tension applied?

The correct value for the length increase of a steel chain per additional 3 lbs of tension applied is 0.001. This figure represents a commonly accepted rule of thumb in surveying and chain measurement practices. When a steel chain is subjected to additional tension, it experiences elongation due to the elastic properties of the material. The amount of elongation is relatively minimal and reflects the strength and resilience of the steel.

In practical terms, understanding this elongation is crucial for achieving accurate measurements in surveying. If a surveyor applies too much tension without accounting for the resulting elongation, the measures taken can lead to inaccuracies in distance calculations. Therefore, knowing that an increase of 3 lbs in tension yields a length increase of about 0.001 allows for appropriate adjustments in measurement techniques.

This value helps professionals in the field maintain precision when using steel chains, thus underlining the importance of tension consideration in surveying tools.