In the safety tensioner threaded tooth on the second moving mode described above by the tensioner manufacturer is connected a screw, the other end of which is connected to the fixing die, and at the driving end of the screw is connected a handle. In said fixed mode is connected a guide rod which is inserted into a blind hole corresponding to the one on the moving mode, and at the limit end of the guide rod is provided a stop shoulder. 2. Secondary die opening mechanism with hook according to claim 1, characterized in that the opening part of the blind hole is provided with a step limiting the corresponding stop shoulder. 3. Secondary die opening mechanism with hook according to claim 2, characterized in that said mandrel is connected by The electric tensioner mechanism for secondary die opening with hooks according to claim 2, characterized in that the protruding end of the core extends into the die cavity. 4. The fixed mode of the secondary die opening mechanism with hooks according to claim 3, characterized in that a handle is provided at the driving end of said core.