If it is with hydraulic overload can be relieved by hydraulic unloading method, one person inching way back open punch.
According to the facts in the powerless, mainly depends on the master's level, that only with the air gun safety block or ball head screw or mold,
It is at the bottom dead point, two people at the same time to see whether the slider can be pushed up, while the clutch pressure will increase, the other person with a large mechanical jack (more than 20 tons) against the crank reverse jack.
It is difficult for a 400 ton pneumatic punch like yours to get stuck, and the slider is just at this position, so it cannot rise and fall, with the least loss
