Provided is a method of manufacturing an insulator including disposing first and second covering members, and swaging the first covering member with the second covering member. The first and second covering members each include a groove and flanges including a perforated flange. The second covering member is disposed on the first covering member such that an inner side of the groove of the second covering member faces an inner side of the groove of the first covering member; the flanges of the second covering member are individually placed on the flanges of the first covering member; and a pin retained on a base is inserted through the perforated flange of the second covering member, to thereby fix the second covering member in position. In the swaging, at least the respective perforated flanges of the first and second covering members are swaged with each other with the pin being inserted therethrough.

Provided is a method of manufacturing an insulator including disposing first and second covering members, and swaging the first covering member with the second covering member. The first and second covering members each include a groove and flanges including a perforated flange. The second covering member is disposed on the first covering member such that an inner side of the groove of the second covering member faces an inner side of the groove of the first covering member; the flanges of the second covering member are individually placed on the flanges of the first covering member; and a pin retained on a base is inserted through the perforated flange of the second covering member, to thereby fix the second covering member in position. In the swaging, at least the respective perforated flanges of the first and second covering members are swaged with each other with the pin being inserted therethrough.