Lock-cylinder arrangement - which comprises a lock-cylinder housing having a locking bit, which is mounted in a pivotable manner in the lock-cylinder housing, having a threaded bore, which leads transversely through the lock-cylinder housing and is intended for accommodating a faceplate screw, and having an actuating-member-accommodating opening, which extends from diametrically opposite end sides of the lock-cylinder housing in the direction of the locking bit, and - also comprises two actuating knobs (3a, 3b), each having an actuating shaft (4a, 4b), which is adapted for introduction into the actuating-member-accommodating opening of the lock-cylinder housing and has a coupling element for coupling to the locking bit, wherein the actuating shafts (4a, 4b) have a locking contour (7a, 7b), which is designed for locking the actuating shaft (4a, 4b) on the cylinder-lock housing, wherein the lock-cylinder housing contains at least one channel (9, 10), which leads from the faceplate-screw threaded bore to the actuating-member-accommodating opening, and a locking member (11, 12) is mounted in the channel (9, 10), and in that the channel (9, 10) is adapted, by way of its locking member (11, 12), to the locking contour (7a, 7b) having an associated actuating shaft (4a, 4b) of an actuating knob (3a, 3b) so that, when a faceplate screw is being screwed into the faceplate-screw threaded bore, the locking member (11, 12) can be shifted with the aid of the faceplate screw and an actuating shaft (4a, 4b) introduced into the actuating-member-accommodating opening can be locked by engagement of the locking member (11, 12) in the locking contour (7a, 7b) of the actuating shaft (4a, 4b), and wherein the locking member has at least two interacting locking pins (11, 12), wherein a first locking pin is arranged in a first channel portion, which opens out into the faceplate-screw threaded bore, and a second locking pin is arranged in a second channel portion of the channel, which opens out into the actuating-member-accommodating opening, and wherein the first and second channel portions (9, 10) merge one into the other and are oriented at an angle in relation to one another, characterized in that, on their end sides which face towards one another, the first and second locking pins (11, 12) each have an oblique surface (13a, 13b), which runs obliquely in relation to the direction of longitudinal extent of the respective locking pin (11, 12), wherein the oblique surfaces (13a, 13b) of the first and second locking pins (11, 12) are adjacent to one another and form a sliding joint or ball joint, and in that the locking member (11, 12) is subjected to prestressing by means of a bracing element, in particular of a compression spring, acting between the lock-cylinder-housing and locking member (11, 12), so that the locking member (11, 12) can be moved out of locking engagement with the associated actuating shaft (4a, 4b). - which comprises a lock-cylinder housing having a locking bit, which is mounted in a pivotable manner in the lock-cylinder housing, having a threaded bore, which leads transversely through the lock-cylinder housing and is intended for accommodating a faceplate screw, and having an actuating-member-accommodating opening, which extends from diametrically opposite end sides of the lock-cylinder housing in the direction of the locking bit, and - also comprises two actuating knobs (3a, 3b), each having an actuating shaft (4a, 4b), which is adapted for introduction into the actuating-member-accommodating opening of the lock-cylinder housing and has a coupling element for coupling to the locking bit, wherein the actuating shafts (4a, 4b) have a locking contour (7a, 7b), which is designed for locking the actuating shaft (4a, 4b) on the cylinder-lock housing,