An electrophotographic photosensitive drum usable with an
electrophotographic image forming apparatus, includes a non-circular
twisted projection provided at one longitudinal end of the drum, and
engageable with a non-circular twisted hole being disposed at a central
portion of a driving rotatable member of a main assembly of the image
forming apparatus, and an electroconductive member provided on the
projection, electrically connected to the drum, and contactable with an
electroconductive member electrically connected with a main assembly of
the image forming apparatus and disposed in the hole to ground the drum.
The contact position between the electroconductive members moves in
interrelation with the projection being moved toward the hole by rotation
of the driving rotatable member when the projection is engaged with the
hole.