The machine, are used for punching shear the cold crimped engine bed with the thickness of 1.2-2.5mm, the width of 2000mm, Material strength of 450N/sqm. The specifications of punching shear are surveyed by the bit of TB5-20 mesh grid plate: if the TB, TL are changed, the punching shear knife is also changed; TB,TL are increased, the pinching shear strength is reduced; TB,TL are reduced, the punching shear strength is increased.