Abstract: A pivotal joint for waveguides provides a low-loss interface between two rigid waveguides at which relative movement can occur. The pivotal joint has two waveguide sections which are terminated in conical surfaces containing concentric chokes to minimize RF energy leakage. A universal gimbal is utilized to position the joints so that the pivotal motion occurs about the apices of the chokes. The advantages of this RF joint include zero bending torque, absence of a fatigue failure mode, low insertion loss and a good impedance match at all angles of operation and over large bandwidths.