A common rail includes a generally cylindrical peripheral wall having a communication passage extending axially therethrough. At least one branch hole extends through the peripheral wall and is aligned perpendicular to the axis of the common rail. The intersection of the branch hole with the outer surface of the main pipe rail defines an outwardly flared pressure receiving seat for receiving the connection head portion of a branch pipe. A sleeve nipple is welded or brazed to the outer surface of the main pipe rail and surrounds the branch hole. Inner surface regions of the peripheral wall surrounding the branch hole have a compression residual stress imparted thereto. The creation of the compression residual stress may cause a portion of the inner surface of the main pipe rail surrounding the branch hole to assume a non-cylindrical configuration.
