Abstract: A soldering iron including an insulator, a dissipator, and a hollow, cylindrical handle through which the electrical cable travels, and in which the wires, extending from the electrical cable and connected to the heater unit by individual plug and socket connectors, are able to move freely for making it easier to exchange the heating element but prevent the wires from being accidentally disconnected by pulling on the electrical cord during use. More specifically, a single electrical insulator body, which fits inside the dissipator, receives all of the electrical connectors. Furthermore, the insulator provides unidirectional strain relief by trapping the wires against an inside tapered portion of the dissipator when mounted within the dissipator and releases the wires in the opposite direction simply by the act of being removed from the dissipator.