Disk wheel (10) of a rotor of a turbomachine of the type equipped with a series of blades (12) integral with a central annular portion (14) which is fitted on a shaft (20) of the turbomachine, the disk wheel comprises at least a first insertable portion (18) of the female or male type situated close to a base end of the central annular portion (14), which is suitable for being coupled with at least a corresponding second insertable portion (38) of the male or female type integral with the shaft (20) so as to increase the reliability of the disk wheel (10) itself.