Metal workpiece cutting machine

The cutting tool comprises a holder with an axle carrying the cutting plate plus a mechanism to turn the plate and axle relative to the holder. The mechanism should be a screw pair parallel to the axis (3) where the holder forms the nut for a screw (12). The screw should have a second order rotation surface (16) contacted by a shoulder (19) on the side of the axle at a point (20) outside a plane through the geometric axis (18,8) of screw and axle. Preferably the rotation surface is a cone coaxial to the screw axis (18) or a surface eccentric to the screw axis. One end of the screw is fitted with a crosspiece for turning it. The screw is turned to bring another face of the cutting plate (4,5) into operation, by keying the squared head (17). The ratio of the turning mechanism (11) depends on the screw thread pitch (14), surface cone angle and distance from the contact point to the plane through the geometric axes.