Abstract: An electrical plug connector half connectable with another matching electrical plug connector half and including a housing having a cable entrance, at least one contact carrier located in the housing, a cap secured to the housing at its cable entrance end, a union overlapping the housing and an end of the contact carrier projecting beyond the respective end of the housing and supported on axially spaced, radially projecting annular webs of the housing forming slide bearing regions, and a safety arrangement for preventing an inadvertent rotation of the union in a direction corresponding to release of threaded connection of the plug connector halves, with the safety arrangement being located in an annular space between the axially spaced slide bearing regions and including a circular saw toothing provided on the union or the housing and at least one spring-biased pawl cooperating with the saw toothing and provided an another of the union and the housing.