An air spray gun for paint has a tubular body, having an integral screw thread receiving a threaded collar. This secures an air cap against the end of the tube. The air cap has four horns, formed with obliquely inwards directed bores, for patterning the spray, by impinging on it from opposite sides in a manner analogous to that of known air caps having two horns. Behind the air cap in the tube is an air distributor for distributing air to either or both of the pairs of air horns as required to patterning of the paint spray. Paint flow is controlled by a needle withdrawable from a paint nozzle. The needle is in two parts, a front interchangeable part and a rear part connected to the trigger.