the pin tumbler lock uses a set of pins to prevent the lock from opening unless the correct key is inserted the key has a series of grooves on either side of the keys blade that limit the type of lock the key can slide into as the key slides into the lock the horizontal grooves on the blade align with the wards in the keyway allowing or denying entry to the cylinder a series of pointed teeth and notches on the blade called bittings then allow pins to move up and down until they are in line with the shear line of the inner and outer cylinder allowing the cylinder or cam to rotate freely and the lock to open