The coupling (4) between two hydraulic components has at least one outer, sleeve-shaped member (5) and one inner member (11). The outer member has pref. an outer thread (8). The inner member is in the form of an open duct (13,14) at one sleeve-shaped end (12). The inner member with its sleeve-shaped part fits from the end (6) of the outer member into a hole (9) in the outer piece and is locked behind a catchface (10) by spreading flaps (19).
