<p>A method of producing an exhaust gas-carrying device in which the gas-carrying device includes at least one insert piece and a cylindrical outer housing is disclosed. The method includes the steps of introducing the insert piece into the outer housing and applying radial forces with clamping jaws which bear against the outer surface area of the outer housing and plastically deform the outer housing inwards in order to clamp the insert piece in the outer housing. The clamping jaws are configured to have edges such that marking lines are formed in the outer housing which do not continuously extend axially parallel to the outer housing along that portion of the outer housing in which the insert piece is arranged.</p>