A structure providing efficient gas heating of forging dies comprising a plurality of bearing bars made of a high strength metal located between the dies of a forging press and respective die supporting structures. The bars are spaced apart to accommodate gas fired burners and layers of heat insulation in such a manner that only the bearing bars receive forging loads, the layers of insulation and the burners, being accommodated in the spaces between the bearing bars, receive no forging loads. The bearing bars are provided with longitudinally extending openings for preheating and conducting the gas (or gas-air mixture) to the burners, and for limiting the conduction of heat from the dies to the die supporting structures. Each die supporting structure includes a plate or platen provided with slots adapted to receive and retain die clamping bolts, the bolts being located between adjacent bearing bars, and extending from the plate to and through respective clamps engaging the edges of the die and portions of at least two adjacent bearing bars extending beyond the edges of the die.