The performance of a hydraulic servomechanism depends largely upon the servovalve characteristics which in turn are determined by various physical parameters such as spool land width, radial clearance etc... The work described in this paper is concerned with the design of hydraulic spool valve for a maximum pressure sensitivity in a no load flow application. It has been demonstrated that this condition is achieved by having an underlap equal to the radial clearance. The results are experimentally verified and the effects of rounded corners of metering lands on the pressure sensitivity curves are discussed.