Cylinder device

A cylinder device comprising:

• a cylinder;
• a rod that is inserted into the cylinder movably in an axial direction;
• and
• a piston that includes a piston main body that is inserted in the cylinder movably in the axial direction and connected to the rod, and a piston ring that is placed in an outer circumference of the piston main body and comes slidably in contact with an inner circumference of the cylinder, wherein
• the cylinder includes a stopper portion that is formed by being caulked from an outer circumferential side and protrudes toward an inner circumferential side of the cylinder, and comes into contact with an outer circumferential end on one end side of the piston main body when the piston moves to a stroke end in one direction in the cylinder, and
• an axial direction distance between a side end of the piston in the axial direction of the stopper portion and a portion of the stopper portion that the piston main body comes into contact with is shorter than an axial direction distance between an end portion on a side of the stopper portion of a sliding surface of the piston ring that comes slidably in contact with the inner circumference of the cylinder, and the outer circumferential end of the piston main body.