A pin setting key for setting rotational orientations of pins of a lock. The key includes a bow portion and a blade portion for inserting into a keyway. The blade portion has a longitudinal axis and a bow end and a tip end, with a plurality of bitting positions located between the bow and tip ends. Each of the bitting positions corresponds to one of the pins of the plug such that insertion of the blade portion into the keyway aligns the bitting position with one of the pins. Each bitting position includes at least one bitting surface configured to rotate a pin when the contact surface of the pin contacts the bitting surface. Each bitting surface is offset from a central location of the respective bitting position. Each bitting surface has an axis extending generally transverse to the longitudinal axis of the blade.

A cylinder lock with a rotating tumbler pin, a sidebar, and a slider has a keyway with a ward projection into the center of the bitting area of a key blade received by the keyway. The tip of each rotating tumbler pin seats on the bitting surfaces remaining to the sides of this center ward of the key, and the tumbler pins that are engaged by the bitting on the side of the key blade do not seat on more than half of the width of the blade. Half the pin width is removed from each tumbler pin near the tip thereof. The key has a bitted section at which one or more bittings are formed and a non-bitted section bitting that is devoid of bitting. The bittings extend at a constant depth to an edge of the key blade.

A locking mechanism is provided for a lock body and a rotatable key plug. The locking mechanism comprises pins having recesses, each of the pins adapted to be disposed in pin bores in the key plug for reciprocal and rotational movement. An elongated spring member simultaneously engages and biases the pins toward a keyway in the key plug. A locking bar moves between a first position and a second position where at least a portion of the locking bar is received in the recesses in the pins. The locking bar is prevented from moving to the second position unless the pins are in a position where the recesses are aligned with the locking bar. Upon insertion of a key in the keyway the pins are moved axially or rotated for aligning the recesses in the pins with the locking bar so the key can rotate the key plug.