| 摘要 |
A process of manufacturing a sheet metal product including an opening surrounded at least partially by a drawn area, the process comprising steps of providing a pair of drawing dies, one having a drawing punch and the other having a drawing cavity adapted for cooperation with the drawing punch, putting a blank of sheet metal between the drawing dies, advancing one of the dies toward the other so that the blank is drawn by the punch and the cavity. The process includes a step of forming a slit in the blank by tearing the blank at an area which corresponds to the opening and which is adjacent to an area where the blank is stretched during the drawing step.
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