MANUALLY OR PNEUMATICALLY OPERATED ADJUSTABLE IMPACT PRESSES FOR MARKING, RIVETING, NUMBERING AND OTHER PROCESSES PERFORMED BY A STROKE OF PRESS. Once adjusted, the impact force remains constant throughout the stroke of the punch, irrespective of any variation in the work dimensions. Neither does the impact force change when the force applied to the lever (manual press) or the air pressure (pneumatic operation) varies after the minimum impact force required has been reached. The punch can work in all the positions. These models feature a built-in antivibration device which prevents double blows.