Patents Assigned to Nakajima Steel Pipe Co., Ltd
  • Manufacturing method for angled steel pipes
    Patent number: 5802903
    Abstract: According to the present invention, angled steel pipes manufactured by cold forming can be manufactured into such angled steel pipes that are soft and highly stretchable over the entire sections thereof, almost free from residual stresses, and have high buckling strength, excellent secondary weldability and sufficient toughness by way of hot draw forming the pipes with an angled steel pipe forming mill.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: September 8, 1998
    Assignee: Nakajima Steel Pipe Co., Ltd
    Inventor: Norio Nakajima