| 摘要 |
PURPOSE: To provide a plate having no metal part protruding from the surface by forming a screw bore from a metal part located between cutout parts, blanking the metal part alternately in the direction of the one and the other plate surface, and flushing the outer surface of the metal part with the relevant metal plate surface. CONSTITUTION: A metal plate 10 has through-holes 11 arranged in a line 12 in the area for manufacturing a screw bore, the through-holes 11 are arranged so that the center of the first through-hole is located at the edge, where only a semicircular through-hole 11a is formed. A bridge 13 is left between the through-holes. When the metal plate 10 is blanked in the direction of the one or the other metal plate surface 10a, 10b in the following processing step, the material of the bridge 13 present between the through-holes 11 is strengthened during the blanking step, and it partially moves into the space formed by the through-holes 11 to form strengthened metal parts 14, 15. Accordingly, the material of the first bridge can be prevented from protruding from the edge of the metal plate in blanking.
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