| 摘要 |
Circular cylindrical bodies (2) are formed from rectangular sheet-metal blanks by rounding and longitudinal seam welding. These are widened oval-conically over their whole length in a first expanding operation and then relaxed again. Then the bodies (2) are widened in a second expanding operation so that they acquire their polygon-like, particularly rectangle-like, cross-sectional shape over their whole length. As a result, the bodies are stressed at their marginal regions at the ends in such a manner that these marginal regions do not become undulatory and can therefore be satisfactorily joined with a can cover or bottom.
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