End member, photosensitive drum unit, and process cartridge

An end member to be disposed in an end portion of a columnar rotating body mounted on an image forming apparatus body, the end member comprising:

• a tubular bearing member;
• and
• a shaft member held by the bearing member,
• wherein the shaft member includes a rotating shaft which is rotatable around an axis and movable in an axial direction, and a rotating force receiving member which is disposed in one end portion of the rotating shaft and includes an engaging member to be engaged with a driving shaft of the image forming apparatus body,
• wherein the engaging member is switchable between a posture of being engaged with the driving shaft and a posture of not being engaged with the driving shaft, and
• wherein a maximum static friction coefficient applied when the rotating shaft moves in a rotating axial direction with respect to the bearing member is equal to or less than 0.40 where a force that acts in a direction orthogonal to a frictional force direction is 2.5 to 10.5 N.