| 摘要 |
A threaded joint for steel pipes comprised of a pin 1 and a box 2 each having a threaded portion ( 1 a, 2 a) and an unthreaded metal contact portion ( 1 b, 2 b) exhibits adequate leakage resistance and galling resistance when used for makeup of oil country tubular goods with application of a green dope or even without any dope. The threaded joint has a first plating layer of Sn-Bi alloy plating or Sn-Bi-Cu alloy plating formed on the contact surface of at least one of the pin 1 and the box 2 . The first plating layer may have a second plating layer selected from Sn plating, Cu plating, and Ni plating on its lower side and at least one layer of a lubricating coating, and particularly a solid lubricating coating, on its upper side.
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