A tension rod comprising in its preferred form an outer tube and an inner tube in a telescoping arrangement. The outer tube has an expansion joint structure which can engage the inner surface of the outer tube to hold it in place. A spring stem-wedge-rod structure has a wedge portion with a threaded rod extending therefrom for being threaded through a nut held in the expansion rod structure. The spring stem-wedge-rod structure has a stem extending through a coil spring, and a spring retainer is fixed both to the stem and to the inner tube. Twisting of the inner tube causes the wedge portion to effect the expansion joint structure to be fixed in the outer tube, and the coil spring provides the tension to mount the tension rod between a pair of opposing wall surfaces.