A brake disc manufacturing method, said brake disc being attachable to the axle of a vehicle for braking the vehicle, said method comprising the steps of: processing a rotor comprising an approximately annular plate with a center hole, the edge of said center hole having a plurality of projections projecting inwardly into said center hole; processing a bracket comprising a tubular member, in which openings corresponding to said projections are provided; and integrating or coupling the bracket with the rotor by inserting said bracket through the center hole of said rotor and fitting the projections of said rotor into the openings of said bracket, characterized in that the manufacturing method comprises alternatively one of the following groups of steps: group A the step of diameter-reduction processing to obtain a diameter-reduced portion of the bracket by inwardly deforming at least the region in which said openings are formed in said the bracket; and inserting the diameter-reduction portion through the center hole of said rotor, and coupling the bracket with the rotor by enlarging the diameter of the bracket via outwardly deforming said diameter-reduced portion of the bracket, and fitting the projections of said rotor into the openings of said bracket; or: group B enlarging the diameter of the bracket via outwardly deforming at least the region in which said openings are formed in a side wall of the bracket with the bracket acquired by said bracket-processing step inserted through the center hole of the rotor acquired by said rotor processing step, and fitting the projections of said rotor into the openings of said bracket. processing a rotor comprising an approximately annular plate with a center hole, the edge of said center hole having a plurality of projections projecting inwardly into said center hole; processing a bracket comprising a tubular member, in which openings corresponding to said projections are provided; and integrating or coupling the bracket with the rotor by inserting said bracket through the center hole of said rotor and fitting the projections of said rotor into the openings of said bracket, characterized in that the manufacturing method comprises alternatively one of the following groups of steps: group A the step of diameter-reduction processing to obtain a diameter-reduced portion of the bracket by inwardly deforming at least the region in which said openings are formed in said the bracket; and inserting the diameter-reduction portion through the center hole of said rotor, and coupling the bracket with the rotor by enlarging the diameter of the bracket via outwardly deforming said diameter-reduced portion of the bracket, and fitting the projections of said rotor into the openings of said bracket; or: group B enlarging the diameter of the bracket via outwardly deforming at least the region in which said openings are formed in a side wall of the bracket with the bracket acquired by said bracket-processing step inserted through the center hole of the rotor acquired by said rotor processing step, and fitting the projections of said rotor into the openings of said bracket. group A the step of diameter-reduction processing to obtain a diameter-reduced portion of the bracket by inwardly deforming at least the region in which said openings are formed in said the bracket; and inserting the diameter-reduction portion through the center hole of said rotor, and coupling the bracket with the rotor by enlarging the diameter of the bracket via outwardly deforming said diameter-reduced portion of the bracket, and fitting the projections of said rotor into the openings of said bracket; or: group B enlarging the diameter of the bracket via outwardly deforming at least the region in which said openings are formed in a side wall of the bracket with the bracket acquired by said bracket-processing step inserted through the center hole of the rotor acquired by said rotor processing step, and fitting the projections of said rotor into the openings of said bracket.