| abstract |
A threaded joint for steel tubes comprising a plug and a housing, with a contact surface with a threaded part and a non-threaded metal contact part, in which a solid lubricating film containing one or more kinds of chosen lubricating powders Between graphite, mica, calcium carbonate and kaolin, a copper powder, and a bonding agent, it is formed on at least one of the contact surfaces of the plug and the box. Another object is to provide a threaded joint for steel pipes that allows repeated tightening and loosening of the threaded joint without adverse influences on the human body and the environment, and that has excellent resistance to seizure, anti-oxidant properties and gas tightness. |