US Patent 7665772 Metallic cutting ring

The invention provides for a metallic cutting ring for a screw connection for sealingly connecting a tube to an attachment part, which metallic cutting ring has a tube abutment section and a cutting section which adjoins the tube abutment section in the axial direction. The cutting section having a stop which points radially outward from the outer periphery of the cutting ring and has a stop face, which runs transversely with respect to the cutting ring longitudinal axil, for the attachment part. The stop for the attachment part has an annular peripheral stop edge which projects beyond the stop face.