This minor group comprises machining, metal forming, shaping and erecting trades, including machinists and machining and tooling inspectors; tool and die makers; sheet metal workers; boilermakers; structural metal and platework fabricators and fitters; ironworkers; and welders and related machine operators. They are employed by machinery, equipment, vehicle, aircraft, shipbuilding and other metal products manufacturers; construction and electric power generation companies; tool and die, mould making, welding and machine shops; structural steel, boiler, sheet metal and platework fabrication plants; and by construction ironwork, sheet metal work and welding contractors; or they may be self-employed.