A hollow cone spray nozzle produces the smallest droplet size of any purely hydraulic nozzle. The spiral grooves in the swirl inserts of these nozzles ensure an efficient whirling of the liquid which creates uniform droplets throughout. Tangential hollow cone nozzles contain no inserts and the liquid flows at a right angle, which then creates a whirling rotation inside the nozzle chamber. These nozzles are less prone to clogging.