Abstract: Improved partial turn fastener designed to hold a pair of superimposed panels in fixed registration with each other and allowing release of one panel from the other by merely a partial turn of the knob or screw of the fastener. Featured is the arrangement whereby the panels are maintained together by the pressure applied between a threaded screw and a nut without any intervening springs and the fastening force being determined by the strength of the screw and mating nut. A spring assistance is used for release of the fastener from a partial turn of movement. Locking pin means cooperating with the screw and nut prevent unwanted disassembly of the screw from the nut during unlocking operation.