A screw connection device for connecting two pipes, comprising two pipes with flanged pipe ends, a screw, a nut, and a spacer, wherein the nut includes a receiving space, wherein the spacer is securely received in the receiving space. The spacer retains the first pipe securely in the nut, wherein the second pipe is retained in the screw and can be fastened in the nut by means of the screw. An exterior surface of the spacer has at least one cylindrical section, wherein the spacer has a first end surface and a second end surface. A first projection is provided on the spacer, which engages with the nut in the region of the receiving space such that it is securely accommodated therein. The nut includes an exterior surface with flat sub-surfaces. At least one flat sub-surface includes an indentation to form a detent in the retaining space to secure the spacer in the nut. In one form the exterior of the nut has six flat sub-surfaces and every other flat sub-surface has a detent.
