Abstract: A rack for holding panels, includes a pair of extruded specially-shaped struts (30, 32) at opposite sides of the rack that enable rapid mounting of a panel (11-15) at any height along the struts. Each strut includes a front mount portion (70) that forms a cavity (72) with a front vertical strip-shaped opening (86) and a pair of flanges (82, 84) at laterally opposite sides of the opening and includes an integral column portion (150) that increases resistance to lateral strut buckling. A side of the panel is supported on the mount portion by a screw (102) that passes through a hole (94) in the panel and that threadably engages a nut (104) that lies in the mount portion cavity and against the flanges. The front-to-rear length J of the cavity is short enough to allow a compression spring (106) to fit in the cavity and press the nut against the flanges until a screw can be installed.