Connectors have to be mated and need to be tightened. Some people do it by hand, some use a regular wrench, some use a Torque Wrench.
People who are using nothing but their fingers for tightening, usually undertorque. The electrical performance will vary from tightening to tightening, depending how tired the fingers are. In addition: If the same component is tested several times and by different people using only their fingers for tightening, the electrical performance will vary even more, as different torque will be applied, equivalent to the strength of the individual. But strength does not only depend on the physical ability of the individual, but also one’s perception of what constitutes proper torque. Tightening connectors by hand will result from very loose fits to almost correct fits, but usually always incorrect fits. Tightening connectors by hand is obviously inadequate and not recommendable.
The ones who are using a regular wrench, usually overtorque. Short wrenches may lead to torsional forces that are only a little high, the use of longer wrenches however usually results into applying very high torsion. Overtorquing of up to three times has been seen. This will deform the interface of the connectors, proper test results from then on cannot be obtained anymore.
For proper test results and long life of the connectors the rules need to be obeyed. For each individual connector series a torque has been specified, a torque that ensures proper mating conditions, repeatable electrical performance and guarantees mechanically a long life of the connectors. Using the Torque Wrench guarantees that the connection is not too loose, it also ensures that the connection is not too tight, preventing possible connector damage and impaired electrical performance. Using the Torque Wrench also assures that all connections are equally tight, each time.
Hold the Torque Wrench always at the same point near the end of the handle. Apply force perpendicular to the Wrench, in a plane parallel to the outer conductor mating planes of the connectors. Rotate the connector nut only when tightening the connector. Use an open-end wrench to keep the body of the mating connector from turning, if it is not a fixed test port connector. Position the wrenches within 90° of each other before applying force.
Avoid pivoting the Wrench on your thumb or other fingers, and do not twist the Wrench relative to the outer conductors mating plane of the connectors. This would result into applying an additional and unknown amount of torque to the connection.
Spectrum Electrotechnik GmbH manufactures two different types of Torque Wrenches for most of the connector series:
The Wrench is employing a “Break Point”, when the specific torque has been reached. But having heard and felt the Break, a further torquing would be possible. This Wrench has been designed for people that are sensitive and very conscientious (Series: WE-D.....).
For the smaller connector series that can suffer most from overtorquing, this Wrench has been designed that “Fully Breaks”. After the Break Point has been reached, it almost moves freely in an angle of 90° (Series: WE-B.....).