Abstract: A machine manifold or body having fluid passages defined by relatively thin stainless-steel or other corrosion resistant tubular components embedded within a relatively thick molded plastics casing which serves to give the components strength to withstand the fluid pressures in the passages, and to permit a minimum of the expensive corrosion resistant material to be used. The passages may be formed by different tubular components located and preferably sealed together, or could be constituted by a single lost-wax casting of stainless-steel. Conveniently there is a rubbery layer between the thin metal passage defining components and the surrounding molded plastics casing.