Patent ID: 6745448
Filing Date: 2004-06-08
Classification: B21C,B21D,F16L,Y10T

Abstract:
A method for producing a metal pipe by bending a metal plate having first and second edge sections parallel to each other and by opposing said first and second edge sections, comprising:a first processing step for forming a male portion on said first edge section and a female portion on said second edge section said male and female portions being shaped and disposed to be locked when said first and second edge sections are in a final engaged position; a second processing step for forming a processed article in which said first and second sections are opposed by bending said metal plate; and a third processing step for forming a caulked portion for locking said male and female portions in said final engaged position by deforming at least one of said male and female portions with said male and female portions engaging each other while generating at least one space located between and laterally of said male and female portions when said male and female portions are finally locked in said caulked portion.