Abstract: A hollow extrudate includes a long belt-shaped member produced by extrusion and having hollow portions extending in a longitudinal direction of the member wherein an outer surface of a cross-section of a wall forming the hollow portion orthogonal to the longitudinal direction has a substantially constant shape in the longitudinal direction. The member includes a solid portion extending in the longitudinal direction and interconnecting the hollow portions, the solid portion forming a reinforced portion of the member. The solid portion is formed by enlarging the walls of the hollow portion. The member also includes a first and second extruded region which are pressed together to form the hollow portion.

Abstract: In order to achieve a good mounted state by itself without using other members such as spacers or stabilizers, an enlarged section, which is made by enlarging the inner wall of the hollow portion, is provided in the hollow of the hollow portion having the same contour shape throughout the entire length of the hollow extrudate. Thus, the regions such as the corners of the hollow portion are reinforced by said enlarged section to achieve required rigidity, i.e., position-retaining property.