Abstract: A lock cylinder (1) with a suitable key (2) is described, the lock cylinder (1) comprising a cylinder core (13) rotatably mounted in the cylinder housing (1′) and having a key channel (12) for entry of the key (2), which key (2) has a height-profiled rib (15) topping its broad side, of which the tumbler wards (29) cooperate with the tips of tumbler pins (18a) arranged in a row and consisting of non-rotatable core pins and housing pins in such a way that the tumbler pins (18a) guided in the core/housing apertures crossing the rotary joint (F) between cylinder core (13) and cylinder housing (1′) are aligned in terms of height such that the parting line (T) between core and housing pins (19, 20) aligns with the rotary joint (F). The rib (15) comprises a plurality of control tracks extending side by side in the key insertion direction, which as a consequence of an adapted tumbler pin tip configuration are selectively scanned by individual tumbler pins (18a).