Abstract: A method for making junctions between a first body (A) made of a first material includes a tube (A1) and a second body (B) made of a second material and having a hole (B1) for the insertion of the tube (A1). The method includes the threading (A3) of the tube (A1) for screwing in a corresponding threaded portion (B3) of the hole (B1) in the second body (B), the creation of a recess (B2) in the opening of the hole (B1) in the second body (B) and the creation of a ring (A5) at the end (A2) of the tube (A1), wherein the ring (A5) and the recess (B2) have such a shape and size that the ring (A5) is forced in the recess (B2) producing a plastic deformation and thus a seal through interference between the first and second body.