Abstract: A boring tool with interchangeable tool bit holders is equipped with weight balancing members pivotable about a common fulcrum located on the rotation axis of the fine boring head. The weight balancing members are in the form of circular segments. They are pivoted from their given position about the common fulcrum by means of pull cords fixed thereto. In principle, each pull cord is fixed to each weight balancing member. Thus, a first pull cord fixed to one side of two weight balancing members is guided about a first guide bolt and a second pull cord fixed to the other side of the two weight balancing members is guided about a second guide bolt.