A boring bar for a non-rotating boring tool, the boring bar comprising: - an elongated body configured for attachment to a support structure of a metal cutting machine, the elongated body having a rear end and an opposite front end, the front end being arranged to carry a tool part provided with a cutting element; and - at least two electrically controlled vibration actuators for active vibration damping of the boring bar, each one of these at least two actuators comprising a moveably arranged damping mass and being configured, by movement of the damping mass, to generate vibratory forces in parallel or at least substantially in parallel with a working axis of the actuator that is perpendicular to a centre axis of the damping mass, wherein each one of these at least two actuators is a single-axis actuator having one single working axis, and wherein these at least two actuators are arranged with their working axes angularly offset from each other, characterized in that said at least two actuators are arranged in a longitudinal series in the elongated body with the centre axis of the damping mass of each one of these actuators coinciding or substantially coinciding with a longitudinal axis of the elongated body, wherein the elongated body comprises: • an elongated main part configured for attachment to a support structure of a metal cutting machine, the main part having a rear end and an opposite front end, • a front part having a rear end facing the front end of the main part and an opposite front end, the front end of the front part being arranged to carry said tool part, and • at least one damping module arranged between the front end of the main part and the rear end of the front part and accommodating one or more of said at least two actuators; and wherein the front part of the elongated body is connected to the main part thereof via the at least one damping module, wherein the at least one damping module constitutes a length section of the elongated body. - an elongated body configured for attachment to a support structure of a metal cutting machine, the elongated body having a rear end and an opposite front end, the front end being arranged to carry a tool part provided with a cutting element; and - at least two electrically controlled vibration actuators for active vibration damping of the boring bar, each one of these at least two actuators comprising a moveably arranged damping mass and being configured, by movement of the damping mass, to generate vibratory forces in parallel or at least substantially in parallel with a working axis of the actuator that is perpendicular to a centre axis of the damping mass, wherein each one of these at least two actuators is a single-axis actuator having one single working axis, and wherein these at least two actuators are arranged with their working axes angularly offset from each other, said at least two actuators are arranged in a longitudinal series in the elongated body with the centre axis of the damping mass of each one of these actuators coinciding or substantially coinciding with a longitudinal axis of the elongated body, wherein the elongated body comprises: • an elongated main part configured for attachment to a support structure of a metal cutting machine, the main part having a rear end and an opposite front end, • a front part having a rear end facing the front end of the main part and an opposite front end, the front end of the front part being arranged to carry said tool part, and • at least one damping module arranged between the front end of the main part and the rear end of the front part and accommodating one or more of said at least two actuators; and • an elongated main part configured for attachment to a support structure of a metal cutting machine, the main part having a rear end and an opposite front end, • a front part having a rear end facing the front end of the main part and an opposite front end, the front end of the front part being arranged to carry said tool part, and • at least one damping module arranged between the front end of the main part and the rear end of the front part and accommodating one or more of said at least two actuators; and wherein the front part of the elongated body is connected to the main part thereof via the at least one damping module, wherein the at least one damping module constitutes a length section of the elongated body.