Abstract: This invention provides an oil-well metal pipe which is capable of achieving both high yield torque and excellent galling resistance in a compatible manner. An oil-well metal pipe of the present disclosure includes a pipe main body. The pipe main body includes a pin that is formed at the first end portion, and a box that is formed at the second end portion. A plating layer is formed on a first contact surface, which is one of a pin contact surface of the pin and a box contact surface of the box, and a solid lubricant layer is formed on the plating layer. An arithmetic average roughness Ra of a second contact surface, which is the other of the pin contact surface and the box contact surface, is 0.5 to 10.0 ?m, and a semi-solid or liquid anti-rust coating is formed on the second contact surface.

Abstract: A solid lubricating coating formed on a contact surface of a threaded joint for pipes has a matrix of a lubricating oil-containing polymer. The lubricating oil-containing polymer has either a uniform composition or a gradient composition in which the concentration of lubricating oil decreases towards the contact surface and in which there is substantially no lubricating oil in the vicinity of the contact surface.

Abstract: A solid lubricating coating formed on a contact surface of a threaded joint for pipes has a matrix of a lubricating oil-containing polymer. The lubricating oil-containing polymer has either a uniform composition or a gradient composition in which the concentration of lubricating oil decreases towards the contact surface and in which there is substantially no lubricating oil in the vicinity of the contact surface.