The invention enables a true quick-release connection to a completely standard threaded electrical plug (or receptacle). The mating connector engages the standard threads with a group of radial pins, rather than with conventional, circumferential mating threads. Preferably each pin is generally cylindrical, but has one part (ordinarily a tip) shaped for best engagement with the threads; and another part shaped for engagement with a pin-retracting cam. Most commonly the threads and the thread-engaging part of each pin are complementarily tapered. The connectors are screwed together in a conventional way; but for quick release the cam radially retracts all the pins from the threads simultaneously.