To provide a rotary-printing machine provided with a torsion bar setting device for adjusting and holding a torsion torque amount of a torsion bar equipped to the rotary-printing.

The rotary-printing machine is provided with a fixing means for fixing one side shaft end of the torsion bar in a circumferentially twisted state and the torsion bar setting device to which a cam follower is pivoted to the other shaft end of the torsion bar. The rotary-printing machine is also provided with a gear formed on a part of the outer peripheral face of a bearing provided on the fixing means, a pinion engaged with the gear formed to the fixing means, and a bearing bracket for axially supporting the pinion. In this way, the control of the torsion torque is directly executed with an energizing means. Therefore, required minimum torque can be accurately set. The contact pressure of the cam follower can be stabilized. As a result, it is possible to prevent the occurrence of operation failures of the printing machine caused by a cam jump or the like when the torsion torque is short.