Abstract: The invention concerns a new type of tool for engraving machines comprising an oblong body (11a) provided at one end of an insert-receiving (19) pocket (18).Said insert includes a cutting tip end (19a) at one end, one rear surface (23), as well as an intermediate surface in the shape of a cylindrical body (22) truncated by an oblique flat piece (24), the section of said cylindrical body (22) tapering away from said tip end (19).Said oblong body (11a) is provided with a pocket (18) including a cylidrical wall corresponding to that of the cylindrical body (22), as well as a wall slanted in such a way as to be adapted to the obliquity of the flat piece (24), the surface of said wall (25) exhibiting a convexity in a radial and/or longitudinal direction so that said insert (19) can be inserted and maintained in said oblong body (11a) by jamming the flat piece (24) in the pocket (18).