Abstract: A binder lock mechanism includes a manually adjustable locking bar and co-operative locking-hook parts. Pair-wise mutually overlappable locking-hook parts are connected with and project from a respective binder end half, and are situated at mutual distances from each other. The binder end halves are connected by an intermediate pivot joint. The pair-wise mutually overlappable locking-hook parts present openings adapted to receive a respective lock lever connected with the locking bar and have a respective lock lever permanently received on a common binder end half in a mating opening in an assembled state. The lock levers are arranged at a tip portion and at a waved part, respectively, of the locking bar in such a way that they are situated on a common line through the bar, which is retained by a counter-directed resilient tongue situated on the locking bar and a stopper and co-operatable counter-stoppers situated on the binder end.