Abstract: A hub body for clutches, especially friction clutches in motor vehicles, with internal toothing for connection to a gear input shaft and with at least one encircling shoulder extending radially outward or with elements spaced in the circumferential direction and extending radially and axially for connection to a take-along disk of the clutch. The hardness curve in the shoulder or in the elements rises in the axial direction, relative to a constant axial plane, from a minimum value to a maximum value and declines again, and the hardness curve declines, relative to a constant radial plane, from a maximum value on the radial inside to a minimum value on the radial outside.