... 2.Foot pedal, 3.Punching tool and lower die, 4.Torsion bar, 5. Hydraulic system6. Back gauge, 7. Upright, 8. ... stress--Two cylinders controlling beam’s vertical moving--Mechanical torsion synchronization--Integration hydraulic system--Motorized back gauge with ... synchronization system--Mechanical-hydraulic synchronization system, which use a torsion bar to ensure the parallelism between beams, it’s a ...