Semiautomatic assembling machine suitable for the production of hollow elements, made out of segments of tube, whose sides are closed by cut-off pieces made in solder-filled gold plate. These elements are necessary for the production of watch-bracelets, barrel shaped locks, hand made chains, findings etc. The tube segment are manually inserted in the machine, and with a simple pneumatic movement the machine cuts the sides of the required shape, makes the holes in the sides and inserts the sides on the tube segment.