Abstract: Ends of several electrical wires are joined by a connector which is twisted onto the wire to a predefined torque level by using a unique tool socket. The connector has a body with closed end and an open end for receiving the electrical wires. At least a portion of the hollow body has an equilateral polygonal cross section shape formed by side surfaces which meet at corner sections. The tool socket includes a coupling through which torque is applied and has an aperture for receiving the connector. The aperture has a cross-sectional shape such that the tool socket engages only the connector corner sections and a space exists between the connector side surfaces and the socket. That engagement concentrates torque applied by the tool socket to the connector which causes the corner sections to round upon application of more than the predefined torque level, thus preventing excessive torque from being applied to the connector and the wires.