Abstract: There is disclosed a method for hot lubricated metal extrusion in which a billet is extruded into a solid or tubular form by means of a die and/or a mandrel with an organic lubricant interposed within a container, the method comprising feeding a combustion improver or a mixture of a combustion improver and water into an extruded product thereby burning off the carbide of the lubricant deposited on the surfaces of the extruded product.

Abstract: A die for use in a hot hydrostatic extrusion process, in which a billet comprised of aluminum or an aluminum alloy or a billet having aluminum and an aluminum alloy at its outer periphery is preheated and charged into a container whereupon extrusion is carried out by means of a pressure medium, said die comprising a plurality of stepped conical portions serving as approach portions to the die outlet; said conical portions having conical surfaces whose opening angles increase from the inlet of the die toward the outlet thereof, said conical surface which is closest to said inlet having an opening angle of less than 60 degrees, and the difference between the opening angles between adjacent conical surfaces being less than 90 degrees.

Abstract: A method and machine for use in hydrostatic extrusion wherein a portion of an elastic-plastic viscous pressure medium is introduced into the rear portion of a container, with the rear end thereof being sealed in a fluid tight fashion. The pressure medium being of such a nature that it has a high viscosity and cannot flow by itself. Subsequently, a billet is charged into the container and then a die is mounted in the container at the forward end thereof. The aforesaid pressure medium is caused to fill around the outer circumferential surface of the billet. In this respect, a high pressure seal is provided for the junctions between the die and the forward end of the container and between the die and the forward end of the billet before the pressure medium flows out of the container in a practically negligible small amount, immediately after which a pressure stem is pushed into the container from the rear end thereof, thus proceeding with the hydrostatic extrusion.

Abstract: There are disclosed herein a method and an apparatus for manufacturing tubes or tubular bodies by means of hydrostatic extrusion, which tubes or tubular bodies have axially running holes therethrough having cross-sections of irregular shapes. The method and apparatus utilize a mandrel of novel construction which comprises a conical tip portion having a smooth peripheral surface, a cut or grooved intermediate portion with a sloped groove starting at a peripheral edge and a body portion formed with a flange and adapted to move longitudinally of a pressure chamber, as necessary. The conical tip portion is specifically intended to seal against the conical end of a metallic billet. Unless there is such a provision, there would be leakage of a fluid through the grooved portion because of direct contact of the grooved edge with the inner end surface of the billet.