Abstract: The invention relates to a high voltage insulator of ceramic material, which includes a longitudinal shank having molded sheds and to whose ends of the shank metal caps are shrink-fitted. The ends of the longitudinal shank are enlarged so that the diameter of the enlarged ends is at least 1.05 times the diameter of the longitudinal shank. The cylindrical surface, and the end face of the enlarged ends of the longitudinal shank are machined.

Abstract: A composite insulator includes a FRP core rod and a sheath which is formed by integrally molding an insulating polymeric material to cover the core rod over substantially the entire length thereof. The sheath is composed of a plurality of molded portions which are aligned with each other in the axial direction of the core rod. Adjacent molded portions of the sheath are arranged relative to each other so that a gap is left between the opposite ends of the molded portions. The gap is filled by a joint insulating material which is integrally united to the polymeric material of the adjacent molded portions.