Patent ID: 7866706

Claim:
A threaded joint for a steel pipe comprising a pin and a box with a contact surface having a threaded part and an unthreaded metal contact part, wherein a solid lubricating film containing at least: a copper powder of which length of the longest part is 1 to 20 μm; a binder, and one or more kinds of lubricating powders selected from the group consisting of graphite, mica, calcium carbonate and kaolin, is formed on at least one contact surface of the pin and the box, the copper powder is dispersed in the solid lubricating film, wherein a surface of the copper powder is inactivation-treated, thereby the copper powder has a copper oxide film, a copper sulfide film, or a film of a metal inactivating agent selected from benzotriazole or thiazole on the surface of the copper powder, and the solid lubricating film is substantially free from molybdenum disulfide and tungsten disulfide.