An intake manifold is disclosed which has an upper shell portion having a first peripheral flange, a lower shell portion having a second peripheral flange, and at least one metallic post having a first plate and a second plate. The first and second peripheral flanges are friction welded and the first plate of the posts is friction welded to the upper shell portion and the second plate of the posts is friction welded to the lower shell portion. The upper and lower shells are made of a polymeric, or plastic, material. The metallic post is comprised substantially of aluminum or other suitable metals or alloys. The upper and lower shell portions define a cavity and a section of the post between the first and second plates traverses through the cavity.