For a bolt length more than 4 diameters but less than 8, what is the required nut rotation?

When the bolt length is more than 4 diameters but less than 8 diameters, the required nut rotation specified in the standards is two-thirds of a turn. This amount of rotation is necessary to ensure proper tightening and the establishment of an accurate preload within the connection.

This rotation helps to accommodate the necessary elongation of the bolt as it is being tightened. When the nut is turned two-thirds of a turn, it provides sufficient tension to effectively clamp the connected parts together while also allowing for the appropriate level of stress within the bolt itself without risking over-tightening. The specific requirement helps maintain the integrity of the structural connection, ensuring safety and performance under load.

Understanding this concept is crucial for ensuring compliance with industry standards in structural bolting applications, where precise measurements and rotations directly affect the effectiveness and safety of the connection.