a method of manufacturing gas and / or fuel swirlers for fuel injectors and combustor domes and cone - shaped swirlers so manufactured are disclosed . the disclosed conical swirlers feature cut - through slots on a cone - shaped body . the contour and spacing of the slots are configured and arranged to accommodate a wide range of requirements for fluid flow areas and swirl strengths . preferably , the cone - shaped swirlers can be manufactured by wire edm processing . more preferably , multiple cone - shaped swirlers can be manufactured simultaneously by nesting swirler blanks in a stack and wire edm processing the stack as a unit . the cone - shaped pinwheel swirler fits well into various fuel injector heads , enabling the injectors to reduce the frontal surface area and flat area for minimal potential of carbon formation .