An air swirler has a radially outer wall bounding an annular passage. The radially outer wall has an axially extending portion and a radially convergent portion which converges towards an outlet of the passage. Downstream of the outlet, the passage facing surface of the radially outer wall becomes divergent. The region in which the passage facing surface of the radially outer wall is convergent then divergent defines the flare. A circumferential and axially extending recess is provided in the radially outer wall opposite the flare. A reinforcement of material with superior wear properties to the material of the main body is built in the recess to a radius which coincides with that of the outer surface of the axially extending portion of the radially outer wall. The reinforcement can conveniently be added to the main body by means of a laser consolidation ALM process.