A spray bar having a plurality of laterally spaced nozzles mounted in a row on a header block for discharging a row of liquid spray patterns, and a method of manufacture. The spray bar header includes a plurality of separate plates, each formed with a plurality of nozzle-receiving apertures and with one or more faces of adjacent interfacing plates being formed with grooves which define fluid passages for the supply liquid, atomizing and nozzle-actuating air, and heating fluid. The plates preferably are electroplated/electropolished for thorough and efficient cleaning upon disassembly.