To provide boss and brake rotor parts for an automobile wheel.

In a wheel part which includes a boss and a bearing device, an annular boss 10 has a cylindrical seat 14 in an axial direction to which an outer ring 17 of a bearing 11 is inserted by radial interference. The ring 17 is fixed on the boss 10 in an axial direction between a pair of annular rims 22, 23 which are radially projected to the outside from an outer cylindrical surface 21 of the ring 17 and deformed at low temperature so as to mesh two opposed surfaces 18, 19 of the boss 10. The boss 10 also has an outer radial flange 12 for fixing a brake rotor 26 successively having the flange 12 and an inner radial flange 27 practically arranged in the same surface. A brake rotor 26 is fixed on the boss 10 in an axial direction by at least an annular rim 29 deformed at low temperature which is radially projected to the outside from the flange 12 on the boss 10 to mesh each one of two radial surfaces 30, 31 of the flange 27.