Abstract: A nozzle for providing a high discharge velocity of a fluid fed to the nozzle comprises a pipe having an orifice at one end, at least the portion of the pipe adjacent the said one end being internally tapered towards the orifice. An insert member having an externally tapered portion substantially conforming to the internal taper of the end portion of the pipe is located in the said end portion. At least one of the tapered portions of the pipe or insert member has a groove establishing a fluid connection between the interior and exterior of the pipe. The nozzle may form part of a fluid injection device having a manually operable plunger slidably mounted in the pipe for ejection of fluid from the nozzle.