For a bolt length less than four times the bolt diameter, what is the required nut rotation beyond snug tight for the turn of the nut method?

For a bolt length that is less than four times its diameter, the required nut rotation beyond the snug tight position when using the turn-of-the-nut method is indeed one-third of a turn. This approach is essential for ensuring that the connection achieves the necessary tension and clamping force.

When the bolt length is relatively short (i.e., less than four times the diameter), it indicates that the bolt will have limited elongation, which is crucial in producing adequate preload. The industry standard has identified that one-third of a turn past snug tight is sufficient to achieve the required tension while mitigating the risk of over-tensioning. This amount of rotation allows for proper engagement of the threads and ensures a secure connection without the threat of damaging the assembly through excessive torque.

Understanding the significance of this method is fundamental, as it directly affects the performance and integrity of bolted connections in structural applications. Properly following these guidelines ensures the reliability and safety of structures that rely on these critical components.