Assembly tool for plug connections

Considerable forces have to be applied when pushing plug sleeves onto plugs since the sleeve must initially be expanded by the plug before the actual plugging-on process starts. According to the invention, a pistol-like assembly tool can be used for this purpose, by means of which for example flat plug sleeves can be pushed onto the mating piece with which contact is to be made. A tool holder, an impact hammer and an adjustable compression spring are arranged such that they can move axially on a guide column.