A method of manufacturing turbine engine casings having at least one boss includes, in one exemplary embodiment, forming an engine casing having an outer wall, machining a tapered opening through the casing outer wall, and machining a tapered portion in a metal plug where the tapered portion is sized to mate with the tapered opening in the casing outer wall. The method also includes inserting the metal plug into the tapered opening in the casing outer wall, and welding the metal plug to the casing.