A showerhead assembly for distributing gases within a processing chamber is provided. In one embodiment, the showerhead assembly includes a cylindrical member having a faceplate coupled thereto. The cylindrical member has an outwardly extending first flange at a first end. The faceplate is coupled to a second end of the cylindrical member and has a plurality of holes formed though a center region of the faceplate. The joint between the cylindrical member and the faceplate allow for relative movement when subjected to thermal stresses. In another embodiment, at least one clamp member retains the faceplate to the second end of the cylindrical member.