PURPOSE: To make it possible to firmly joint two parts with each other by making flanges of aluminum, and by press-fitting them into a steel pipe heated at both ends thereof after press-fitting a steel shaft into the flanges so that they are secured by shrinkage fit.

CONSTITUTION: A steel pipe 1 has required dimensions, and flanges 2 are made of aluminum 4. A shaft 3 obtained by being cut off from a steel material and serving as a bearing section, is press-fitted into the flanges 2. The flanges 2 provided with the shaft 3 are then shrinkage-fitted into a predetermined steel pipe 1. The heating of both ends of the steel pipe 1 is made during passing through a heater 5 in a process of automatically supplying the steel pipe 1 by a conveyer 6 or the like, to a predetermined position for the press-fit of the flange. Further, in order to ensure the center line of the flanges 2 at both ends and the pipe 1, they are set on a jig, and therefore, the flanges 2 held on a holder 7 attached to the front end of a rod in a hydraulic cylinder are press-fitted at both sides, simultaneously.