US Patent 10252318 Die apparatus and method for blanking thin plate

A die apparatus includes an upper die and a lower die used for blanking a thin plate, a stripper which is formed on the upper die and is arranged between the upper die and the lower die, and a punch which blanks a part of the thin plate. The stripper or the lower die is provided with a protruding part which reduces flexure of the stripper occurring when a test punching is performed by actuating the punch without the thin plate.