An improved sec-saw, comprising a number of parts which are joined together by means of conventional fixing elements, such as screws and the like, the parts consisting of side supports (1), a part (2) connecting the same, a tubular structure (3) consisting of two identical parallel tubes connected at their central areas, end tracks (4), double end seats (5) and their respective lower stops (5a), a holding part (6), a tube (7) to which said holding part is fixed, handles (8) which are press-fitted in the respective seats, threaded bushes (9) for fixing the connecting part to the side supports, and bushes (10) for fixing the tube (7) to the side supports (1) (figure 19).