PURPOSE: To always maintain the whole area contact of a heating member with a metal die by a method wherein a taper surface part is provided on an outer peripheral surface of an extruder die, and a ring-form heating member provided with an inner peripheral surface, which is so tapered as to fit said taper surface part, is brought into pressure contact with the outer peripheral taper surface part by a resiliently pressurizing means at its inner pheripheral taper surface.

CONSTITUTION: In an extruder metal die 1, a core 12 is contained in an outer cylinder 11 by being supported by a spider 13. A taper surface part 14 is provided on the outer tip end of the outer cylinder 11. A flange 16 is provided on the taper surface part 14 through a heat insulating slit 15. An inner peripheral taper surf ace 24 is formed on a ring-form heating member 2 so as to fit the taper surface part 14, thus being brought into contact with the surface part 14. A compression spring 3 is loaded on a bolt 31 inserted through the heating member 2 and the flange 16. Therefore, if the heating member 2 is thermally expanded or shrunk relatively to the die 1, the spring 3 can always keep a contact pressure constant without an occurrence of a gap between the both, thereby ensuring that a constant thermal conduction from the heating member 2 to the die 1 and a rapid die temperature control result in a product being improved.