DIE SET

PROBLEM TO BE SOLVED: To provide a die set for a differential step bending, which securely provides an exact shape and dimensions of a required differential step bent without occurrence of any crack and fissure or tear off at bent corners. SOLUTION: The die set is composed of a blanking punch 32 to form a through hole for forming a patch near the differential step bent of a work 1 and an upper die vertically movably providing a differential step bending punch 33 and a lower die that faces the upper die and installs a differential step bending die 43 as well as a punching hole 51 mounted on a die plate 47. This configuration allows the work 1 to elongate smoothly and sufficiently around the bent portion of the differential step.