METAL PIPE FOR OIL WELL

Claims

A metal oil well pipe with excellent resistance to seizing is provided. A metal oil well pipe (1) according to this disclosure includes a main pipe body (10), and the main pipe body 10 includes a stem (40) formed into a first end portion (10A) and having a stem contact surface (400) that includes an external thread portion (41), and includes a socket (50) formed into a second end portion (10B) and having a socket contact surface (500) that includes an internal thread portion (51). The metal oil well pipe (1) according to this disclosure further includes a Zn-Ni alloy plating layer (100) formed on a stem contact surface (400) and / or a socket contact surface (500), the Zn-Ni alloy plating layer (100) consisting of 9.0 to 20.0% by mass of Ni, with the balance being Zn and impurities, a precipitate phase includes a γ phase, and a crystallite diameter D (nm) of the γ phase and a Ni content [Ni] (% by mass) satisfy formula (1). D ≤ 12.3 × [Ni] - 81.6 (1).