Abstract: The invention relates to a device for locking pipe and hose couplings of the type comprising two complementary, radially fixed members provided with external, radial abutment surfaces facing on both sides in the axial direction for arcuate locking elements meshing with said abutment surfaces and having inwardly extending end edges, said locking elements being adapted to be fitted over the coupling members and being fixed against radial displacement by a means in the form of a cut ring enclosing said members.The novel feature is that the enclosing means as well as the locking elements are provided with portions for positive interlocking in fixed condition.