Abstract: A method and apparatus for performing a unified metal alloying of jet stacks without the use of a bond press, and without the use of a continuous belt driven furnace. The method may include horizontally stacking fusible parts onto a fixture and transporting the fixture into an interior of a reaction chamber of a diffusion furnace. An operator may seal the interior of the reaction chamber and the diffusion furnace may increase a temperature of an atmosphere of the interior of the reaction chamber to a predefined dwell temperature to perform a first level alloying for a predefined dwell time. The diffusion furnace may thereafter increase the temperature of the interior of the reaction chamber to a predefined brazing temperature to perform a second level alloying for a predefined brazing time.