Abstract: A mechanical rotation limiting connection, defined between the end of a rigid metal cross-over tube and the adjacent end of a fuel rail, is disclosed. The coupling comprises a fitting that is inserted into, and permanently joined to, an open end of the fuel rail. The fitting includes a body complementary in shape to the fuel rail, with an enlarged flange at its trailing end, a tapered leading section, and an axial bore of stepped configuration. The leading section of the cylindrical cross-over tube is deformed into a polygonal shape that fits into the bore of the fitting; a transition section and a round section extend inboard of the leading section, and an enlarged annular collar encircles the cross-over tube. The leading section of the cross-over tube is inserted into the fitting, and mechanical members on the fitting are deformed or crimped over the annular collar on the cross-over tube to lock the tube within the fitting, and prevent inadvertent disassembly.