Wheel-mounted brake disks which are arranged on both sides of a wheel base of a railway wheel and are fastened by through bolts, the bolt head of every through bolt lying in a countersink of one wheel-mounted brake disk and a nut screwed onto the through bolt lying in a countersink of the other wheel-mounted brake disk, each resting either directly or indirectly on the bottom of the countersink. The wheel-mounted brake disks are designed so that every countersink has an undercut portion that extends down to the bottom.