JH21-80 is an open fixed table, pneumatic friction clutch press with a nominal force of 80 tons (800 kN). The stroke of this punching machine is about 130mm, and the nominal force stroke is 5mm (the nominal force refers to the ability of punching machine to achieve full load within how many mm from the bottom dead point). As the nominal force stroke of the 80-ton punching machine is about 5mm, then the 5mm plate can be blanked and punched. According to the actual pressure curve, the farther away from the bottom dead point, the stamping tonnage of the press will be reduced (discounted), otherwise it will cause torque overload and damage the transmission components.Therefore, it is recommended that as long as the 80-ton punching machine can be pressed within 10mm of the plate within the allowable range of the pressure curve, and the tonnage should be in the curve, and more than 5mm of the plate should pay attention to the stiffness and rebound of the punching machine.