A hub bearing unit includes a radially outwardly extending flange, a first portion on a first side of the flange and a tubular portion on a second side of the flange. A bearing outer ring surrounds the first portion, and rolling elements are mounted between the first portion and the outer ring. A splined shaft of a constant velocity joint extends into the hub and has a threaded end portion inside the tubular portion. A threaded connector is mounted on the threaded end portion and has a deformable portion configured to be deformed to prevent the threaded connector from being unscrewed. A portion of the tubular portion near the flange includes a radial through hole configured to allow a torque arm of a deformation tool to access and deform the deformable portion.