A cylindrical base body of the disclosure includes an outer peripheral surface and an end surface which is connected to the outer peripheral surface. The outer peripheral surface includes a first inclined surface which is inclined inwardly toward the end surface, the end surface includes a second inclined surface which is inclined inwardly toward the outer peripheral surface and is connected to the first inclined surface, and a connecting portion of the first inclined surface and the second inclined surface has a radiused surface.