Cylindrical case

A cylindrical case comprising:

• a cylindrical case main body;
• and
• a connecting ring body fitted and fixed to an outer circumferential side of a peripheral wall at a first end of the case main body, the connecting ring body having an annular groove open in a centrifugal direction, wherein
• the connecting ring body has a fitting portion,
• a reinforcement body is fitted to the fitting portion of the connecting ring body,
• the reinforcement body has an arc-shaped groove continuing to the annular groove of the connecting ring body in a state where the reinforcement body is fitted to the fitting portion of the connecting ring body, and
• in the state where the reinforcement body is fitted into the fitting portion of the connecting ring body, the reinforcement body on the peripheral wall of the case main body is brought into contact with an outward receiving wall protruding in a centrifugal direction formed on the connecting ring body and is fixed, whereby the reinforcement body is positioned with respect to the case main body in an axial direction and a radial direction, respectively.