Clamping tool with tightening torque control comprising • a body, containing control circuits and an electronic processing unit and having at one end a handle for the grip of an operator who performs the tightening, and at the other end an arm, • said arm comprising at its free end a seat wherein a plurality of inserts (17, 17', 17") can alternatively be inserted, suitable for engaging the tool with a corresponding type and/or size of a mechanical member on which the tool is intended to act to perform a tightening operation, • sensor means for detecting the tightening torque exerted on said mechanical member, • said sensor means comprise a first torque sensor and a second torque sensor arranged respectively in a position of the arm at a distance from the free end of the arm itself and the second one in a position of the arm at a distance from the end of the arm itself, such sensors being able to detect the torque exerted by a tightening operation in these points and and to transmit this detection to the processing unit of the tool which calculates the torque exerted at the point of application on this mechanical member, • such point M being placed at a known distance Lc from the end of the arm, • the calculation of the torque exerted at the point of application is performed by calculating a bending moment along the longitudinal axis of the key that increases linearly distributed along a straight line R, by means of the two measurements in points M1 and M2 calculating the slope of the straight line R, and from the slope of the straight line R and the known distance Lc, the bending moment at point M is obtained, which identifies the rotation axis of the mechanical member to be tightened and the tightening torque in M, characterized in that each sensor comprises a Wheatstone bridge having four strain gauge grids that form a sensitive element, each bridge has two strain gauges mounted on the traction side, and two on the opposite compression side on cells arranged in this arm. • a body, containing control circuits and an electronic processing unit and having at one end a handle for the grip of an operator who performs the tightening, and at the other end an arm, • said arm comprising at its free end a seat wherein a plurality of inserts (17, 17', 17") can alternatively be inserted, suitable for engaging the tool with a corresponding type and/or size of a mechanical member on which the tool is intended to act to perform a tightening operation, • sensor means for detecting the tightening torque exerted on said mechanical member, • said sensor means comprise a first torque sensor and a second torque sensor arranged respectively in a position of the arm at a distance from the free end of the arm itself and the second one in a position of the arm at a distance from the end of the arm itself, such sensors being able to detect the torque exerted by a tightening operation in these points and and to transmit this detection to the processing unit of the tool which calculates the torque exerted at the point of application on this mechanical member, • such point M being placed at a known distance Lc from the end of the arm, • the calculation of the torque exerted at the point of application is performed by calculating a bending moment along the longitudinal axis of the key that increases linearly distributed along a straight line R, by means of the two measurements in points M1 and M2 calculating the slope of the straight line R, and from the slope of the straight line R and the known distance Lc, the bending moment at point M is obtained, which identifies the rotation axis of the mechanical member to be tightened and the tightening torque in M,