To provide a forming method of a protruded hollow shaft which can suppress occurrence of cracks at the tip even when the height of the protruded shaft formed integrally with a metal plate is increased.
In the protrusion forming step, a plastically workable metal plate 1 is placed on a first die 4 and a pressing tool 5 with a drill-shaped tip is forcibly pressed from one side of the surface 1a of the work to the other side 1b to form a protrusion 6. Then, in the protruded shaft forming step, the work is placed on a second die 7 which has a hole whose inner diameter is almost identical to the protruded shaft 6 and the center of the protruded part 6 is pressed and pierced to the side 1a by a burring tool 8 with the drill-shaped tip. The material of the part 6 protruded on the side 1a of the metal plate 1 is moved by pressing and piercing the burring tool 8 into a hole 7a of the second die 7 to form the protruded hollow shaft 2.
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