Threaded connection for steel pipe

Abstract

A method for assembling a threaded connection for a steel pipe, which connects a first pipe formed with a pin having a truncated cone shape at an end thereof, and a second pipe formed with a box having an opening end. The pin includes a male thread portion, which is a tapered thread, and a seal portion, which includes a tapered surface. The box includes a female thread portion, which is a tapered thread, and a seal portion, which includes a tapered surface. The tapered surface of the pin has a minimum diameter smaller than a maximum diameter of the tapered surface of the box. The method includes making-up the male thread portion and the female thread portion by screwing, whereby a root of the male thread portion and a crest of the female thread portion come into contact with each other after the seal portion of the pin and the seal portion of the box come into contact with each other.

Dependencies are inferred from the claim text.