PURPOSE: To set easily a rotary angle position in case of installing a titled die by cutting and forming a reference surface on the outside circumferential surface of a mandrel and a die, in the titled die constituted of the mandrel and the die.

CONSTITUTION: A mandrel reference surface 10 and a die reference surface 11 which are cut and formed vertically from the outside circumference of a mandrel 1 and a die 2 of an Al extruding die are provided on said respective outside circumferential surfaces. The surfaces 10, 11 are based on mandrel and die bearing surfaces 6, 7 for constituting a bearing part 5, and are formed, for instance, in parallel to them. As a result, a relative relation of the surface 10 or 11, and the bearing part 5 becomes clear, and when the Al extruding die is installed basing on the surfaces 10, 11, its rotary angle position can be set easily to a desired angle position. Accordingly, there is no possibility that the Al extruding die material having a sectional shape corresponding to a shape of the bearing part 5 is deformed.