| abstract |
threaded steel pipe joint is a threaded steel pipe joint with excellent seizure resistance, rust prevention properties, and airtightness without the use of a compound grease comprising a pin and a housing each with a threaded part and a non-threaded metal-to-metal contact portion that serves the contact surfaces. the contact surfaces of at least one of the pin and the housing are coated with a multilayer structure comprising from the bottom a first layer formed from a first metal or alloy, a second layer formed from a second metal or alloy that is softer than the first metal or alloy, and an upper layer of a solid lubricant coating comprising a lubricating powder in an organic or inorganic binder. |