Spline forming method for hub unit, hub unit, spline forming method for joint, and joint

Splines, which are to be meshed with a joint that transmits torque to a rotary ring of a hub unit, are formed in a side face of the rotary ring, the side face being on one side of the rotary ring in the axial direction. Spline grooves are formed in the side face by subjecting the side face to broaching.