Abstract: Disclosed is a method and apparatus for hot forging an elongated cylindrical hot billet formed of lightweight metal alloy or metal matrix composite material into an integral high strength structural member having at least two extensive walls projecting outwardly in different directions from the billet axis, with principal metal grain structure running approximately parallel to the outward extent of the walls. The hot forging is accomplished by bringing a plurality of radially convergent hot die segments from a full open release position to an intermediate position where they first convergently engage the hot billet, and gradually further converging the die segments to a closed position to forge the billet by engaging them with a pyramidal or conical frustum cavity formed in a press member, which cavity conforms to the external configuration of the die segments in the closed position.