A work-piece support member forming part of a spindle liner for use within the hollow spindle of a turning machine comprising: a disc dimensioned to fit closely within the hollow spindle, having a central aperture (A) sized to accept a work-piece; holding at least one helical spring (20) positioned adjacent to the aperture (A); such that in use the axis of said spring is held perpendicular to the axis of said work-piece such that part of the side walls of said spring or springs (20) abut against said work-piece and thereby firmly support said work-piece as it rotates with the hollow spindle about the axis of said hollow spindle.

The invention relates to an insert holder for a tool for turning a machine tool, comprising an insert holder body (2), the head (22) of which is intended to receive a cutting insert (3), characterized in that at least two measurement recesses (4, 5) are provided in the insert holder body (2) on the side of the head (22), said measurement recesses (4, 5) being arranged symmetrically relative to the neutral fiber (6) of the insert holder body (2) and centered on the neutral fiber (6). The measurement recesses (4, 5) have, respectively, a planar bottom (41, 51) that is parallel to the direction (Y) of the component of the tangential cutting force of the insert holder to be measured, and parallel to the longitudinal direction (X, Z) of the insert holder body (2). The insert holder also comprises at least one first strain gauge (71, 72, 73, 74) configured such as to measure the change in shape of the planar bottom (41, 51) of at least one of the measurement recesses (4, 5).

The invention relates to an anti-vibration plug for machining tubes and to a method for placing said plug inside a tube, wherein the plug comprises a central body (2) with arms (3) that open radially outwards intended to come into contact with the inside of the tube (1), a blocking screen (4) being arranged between the central body (2) and the arms (3), which blocks the inside of the tube (1) in the open position of the arms (3), whereas the central body (2) has an axial hole (5) wherein there is housed a piston (6) which movably acts on a peripheral part (8) which surrounds the central body (2) and generates the movement of the arms (3), the peripheral part (8) being subjected to a pushing force exerted by an elastic element (10) in the opposite direction to that in which the piston (6) pushes.