A shear bolt for a junction of electrical conductors includes a tool seat for engagement of the shear bolt by a screwing tool, an externally threaded portion to be screwed in a terminal body of the junction, along a screwing axis, and a tightening portion for engaging an electrical conductor to be tightened in the terminal body. The tool seat is formed at the threaded portion and the tightening portion is connected to the threaded portion on an opposite side with respect to the tool seat. The shear bolt can be sheared in one or more programmed rupture areas in the threaded portion when exceeding a predetermined tightening torque for each of the programmed rupture areas, respectively. Even with the screw unscrewed, the tightening portion is connected to the threaded portion and is rotatable with respect to the threaded portion about the screwing axis and non-detachable from the threaded portion.