The bolt absorbs most of the torque through the shear force in its rod body, and a small portion of the torque is borne by the friction between the flanges caused by the pre tightening load of the bolt. The pre tightened nut does not need to be locked separately.
The bolt absorbs most of the torque by the shear force in its shaft, and a small part of the torque is borne by the friction between flanges caused by the preload of the bolt, so the preloaded nut does not need to be locked separately.