PURPOSE: To obtain highly precise spherical contact between inner race and outer by covering the outside of inner race with outer race made of bearing alloy and then applying a sizing process to the outer race with upside and underside punches.

CONSTITUTION: The inner race 2 of an iron sintered alloy and the outer race 3 of a bronze alloy, etc., are treated with oil and the combined. Then, the mandrel 4 is inserted into the inside hole 2b of the inner race 2 and the die 5 is touched to the outside of the outer race 3. When the pushing sides of the punches 6 and 7 are worked only on the end of the outer race 3 vertically in an annular aperture between the mandrel 4 and the die 5, the sleeve-like outer race 3 is easily deformed plastically so that the outer race 3 is fitted on the spherical surface 2a of the inner race 2 with high accuracy. Thus, a bearing with the inside spherical surface 3a capable of performing a spherical contact can be formed.