Bending of Thin-Walled Tubes by Combined External Mechanical Forces and Internal Fluid Pressure

  • C. Boyd
  • F. W. Travist


Results of tests are described on the ‘Z’ bending of thin-walled tubes in brass and stainless steel using a special purpose machine which employs combined mechanical forces and internal fluid pressure. The two right-angled bends produced by the ‘Z’ bending operation are of fairly small radius of curvature (1.5 times tube o.d.) and of closely held circular cross-section. It is demonstrated how the provision of a controlled internal fluid pressure can eliminate wrinkles and buckles in the tube walls and suppress a tendency to the development of an oval cross-section. Photographs and a line diagram of the forming machine are presented, along with photographs of typical formed tubes.


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Copyright information

© Macmillan Publishers Limited 1972

Authors and Affiliations

  • C. Boyd
    • 1
  • F. W. Travist
    • 2
  1. 1.Now with Munroe and Miller LtdEdinburghUK
  2. 2.Production Engineering DepartmentUniversity of StrathclydeGlasgowUK

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