a multi - part oxy - fuel cutting tip has mixture outlet passages formed by swaging the tip skirt to form grooves . the grooves then cooperate with the tip core to form the outlet passages when the skirt is placed over the tip core . oppositely directed circumferential inlet passages for the preheat oxygen and fuel promote rapid mixing while producing a non - rotating mixture flow . in addition , the sectional areas of the outlet passages decrease in the flow direction . these features promote the rapid creation of a laminar mixture flow .