Abstract: Reciprocal furnace for heating metallic parts to a predetermined temperature has a horizontally reciprocal hearth. The hearth includes a multi-layer firebrick base on which is carried a ceramic fixture adapted to receive the metal parts to be heated in the furnace. The ceramic fixture has a plurality of parallel slots which are longitudinally spaced apart in a direction corresponding to the reciprocal movement of the hearth. The hearth is supported at its underside by a reciprocal drive mechanism and is moved incrementally by a drive motor to advance each slot of the fixture in sequence to a predetermined position at which a part is inserted therein by the reciprocal feed mechanism. After all the slots have been sequentially loaded, the hearth is retracted by the reciprocal drive mechanism to its initial position at which the part, first inserted, is removed and another part is inserted in the same slot. The loading and unloading cycle is repeated continuously.