Heat treatment rotary hearth furnace that can treat parts that weigh up to 1.000 kg. Heating is performed by self-recuperative high-speed gas burners. The furnace has a single door and is divided in rotating chambers as per specific Gadda patented design. The multiple rotating chambers allow precise and separate temperature management of the different zones during the hearth rotation. Rotating chambers block tangential flow in the furnace allowing multiple temperature zones.