Provided is a moulded article in which an additional pad (27) is added and provided as a single piece from an outer surface on the opposite side to a butting side of a flange (17), running over a curved surface on the small diameter side of a curved part (19), up to one end on the outer surface of an article body (13). A clamping seat surface (27f) is formed by mechanical processing on the outer surface of the additional pad (27), and an area end (PAe) of the processed area (PA) which has been mechanically processed is located on the article body (13) side beyond the curved part (19).
