| 摘要 |
An ironing die for use with a punch to reduce the wall thickness of the sidewall of the metal cup includes a body which has a circular opening therein extending from the leading surface to a trailing surface that are parallel to each other and the opening has a land spaced from both surfaces which defines a minimum diameter for the opening. The opening also has a cylindrical portion between the land and the trailing surface which has a diameter slightly larger than the minimum diameter to guide the cup after the free edge moves past the land. The opening is also flared outwardly between the land and the leading surface to produce an entry portion which guides the cup to a centered position with respect to the ironing land. In one embodiment, the wall which defines the opening also has a cut out portion between the land and the cylindrical portion.
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