| 摘要 |
To provide a method of forming a fan with ring in one piece from a single metal plate and to provide the fan formed using the method, the metal plate is plastically worked into a shallow pan shape so as to form a cylindrical ring portion 1 on the periphery. A boss portion 2 is then formed at the center of the bottom portion of the pan shape, cutting all portions, except for part of the front end edge along the radius of each of blade portions 3 and part of the edge of the ring portion 1 for use as connection portions 4 so that the plurality of radial blade portions 3 are slit and formed.
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