Abstract: A scaffold, which is comprised of a plurality of vertical posts and horizontal locking bars crossing those vertical posts, has a plurality of joints at which flanges are arranged to provide connections between the vertical posts and horizontal locking bars. Each flange is rigidly connected to the respective vertical post and has a peripheral portion surrounding the vertical post. This peripheral portion receives a hook of the pawl rigidly connected to the end of the respective horizontal bar and provided with a wedge to ensure engagement of the hook with the peripheral portion of the flange. The thickness of the peripheral portion gradually increases in the upward direction.