| 摘要 |
Prior to the drawing and ironing of a sheet or blank of a material such as untinned low carbon cold rolled steel to form a tubular article such as a can body, the metal sheet is roughened in such manner as to provide an overall, uniformly dense pattern of minute depressions in its surface. Oil or other lubricant is applied to the roughened surface and is retained within these small depressions during the drawing and ironing operation, whereby to reduce the mechanical and frictional forces on the blank and on the drawing and ironing dies and thus eliminate galling of the dies and minimize fracture of the metal.
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