shaft 303 having flat surfaces 306 a circular surface 312 a semi circular pad 316 disposed on the circular surface 312 a circumferential wall 321 extending around an arc of preferably greater than ninety degrees an overhanging flange 327 extending inward from the circumferential wall 321 and an operation key slot 332 formed in and interrupting the circumferential wall 321 and the flange 327 the rear shaft 303 is sized to protrude through the rear opening 114 of the cylindrical shell 100 in a preferred embodiment the rear shaft 303 is threaded so that the connecting member 300 may be retained in the cylindrical shell 100 by a retainer device r2 see fig6 a in a preferred embodiment the retainer device r2 is a threaded nut but alteratively the retainer device may be a friction fit ring spring clip or other like device in the preferred embodiment a radially outward locking plate b is positioned between the retainer device r2 and the cylindrical shell 100 the locking plate includes a through hole for receiving the rear shaft 303 preferably a washer w is provided between the locker plate b and the shell the washer w is fixed to the locking plate b and has a perimeter with a notch n that operates to engage the projection 122 to limit rotation between the connector 300 and the shell in the illustrated embodiment rotation is limited to about 90 u00b0 the locking plate b is held in fixed relation to the rear shaft 303 e g by a hole having flat sides similar to the relationship between the shell and the wall or door e the assembled lock includes the removable plug 200 positioned inside the cylindrical shell 100 engaged with the connecting member.