An approach of slight clearance punching of ultra-high strength steel sheets with a moving die (a) before and (b)
during punching the sheet is shown in Fig. 1. A gap between the moving die and holder was set to automatically
center the die during punching. As the clearance between the punch and moving die is small, the punch and
moving die are not set to be exactly concentric prior to punching of steel sheets. During punching, the moving die
undergoes imbalanced force, and thus the die moves to attain automatic centering. Therefore the correction of
eccentricity between punch and die in slight clearance punching is possible.