JOINT FOR OIL WELL STEEL PIPE

摘要

PROBLEM TO BE SOLVED: To provide a joint for an oil well pipe not allowing generation of galling in a screw part when constructing the oil well pipe, i.e., fastening the joint. SOLUTION: This joint for the oil well steel pipe comprises a pin part having a male screw and a metal-metal seal part in an end of the steel pipe containing >=9% Cr by mass, and a coupling formed with box parts each with a female part and a metal-metal seal part made of the same material in both ends. A Cu-Sn alloy plating layer is formed on the surface of the metal-metal seal part and the female screw of the coupling.