Rotary drill bits

A drill bit has a plurality of radial blades on its leading face which define fluid channels leading to junk slots in the gauge region, cutting elements being mounted along each blade. At least two of the channels are in communication with one another at their inner ends and there is provided, at the communicating inner ends of the channels, an inner nozzle which is angled to direct the majority of drilling fluid emerging from the nozzle outwardly along one of the channels. An outer nozzle is located in the other channel, adjacent its junk slot, and is angled so that the majority of fluid emerging from the outer nozzle flows inwardly along said other channel and towards the inner nozzle.