Cropping of Round Bar Utilizing Plastic Fatigue

  • Hideaki Kudo
  • Kimio Tamura


As an alternative to existing bar and tube cropping techniques, a cropping method is described which utilizes plastic fatigue fracture and consists of roller grooving and subsequent rotary bending. Solid billets thus cropped at an appropriate number of rotations to fracture have flat and smooth cut ends and show no deterioration in ductility in a subsequent side pressing test. The present technique is most suitable for relatively brittle materials, such as high-speed steel, since only several tens of rotations are required to obtain a good cut end. Preliminary experiments in applying this method to tube cropping give promising results. Directions to shorten the cropping time for less brittle materials are suggested.


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  1. 1.
    (Anon.) (1965). Cold-flow shearing, Metalworking Production (27 Oct.), 59.Google Scholar
  2. 2.
    T. nakagawa and K. Miyamoto (1972). Tool life test in cramp shearing of steel bar or wire. Proc. 12th Int. MTDR Conf, Macmillan, 567.Google Scholar
  3. 3.
    Anon.) (1967). Component production by transverse rolling. The Engineer (10 Nov.), 61 1.Google Scholar

Copyright information

© Macmillan Publishers Limited 1974

Authors and Affiliations

  • Hideaki Kudo
    • 1
  • Kimio Tamura
    • 2
  1. 1.Yokohama National UniversityJapan
  2. 2.Mechanical Engineering LaboratoryJapan

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