Abstract: A nozzle system for a rotary drill bit comprising a plurality of elongate nozzle members detachably secured in drilling fluid exit bores in a drill bit body, each nozzle member having passaging therein, the lower portion of which is angled relative to the longitudinal axis of the nozzle member, and a projection and recess arrangement for holding each nozzle member in its bore in a predetermined angular position for directing the drilling fluid to flow in a stream along a line at a predetermined angle and in a predetermined position relative to an adjacent roller cutter of the drill bit for improved cleaning of the cutting elements and the formation.