Agent for forming solid lubricating coating film, oil country tubular goods, threaded joint for oil country tubular goods, and method for manufacturing oil country tubular goods

An oil country tubular goods comprising a lubricating coating film including a solid lubricating coating film, the lubricating coating film being formed in a thread portion, wherein

• the solid lubricating coating film is formed by dispersing two or more types of solid lubricants in a binder resin,
• the combination of solid lubricants comprises:
• graphite in an amount of 50% or more and 90% or less of a total weight of the solid lubricants, the graphite having a scaly shape and an average particle diameter of 10.0 μm or less, and
• one or more solid lubricants selected from the group consisting of:
• BN (boron nitride), mica, talc, MCA (melamine cyanurate), MoS2 (molybdenum disulfide), PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane;
• tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin), and FEP (perfluoroethylene propene copolymer;
• tetrafluoroethylene-hexafluoropropylene copolymer) as other solid lubricants,
• the binder resin contains a PEEK resin having an average particle diameter of 20 μm or less as a main component, the PEEK resin being contained in an amount of 70% or more of a total weight of the binder resin,
• the total weight of the solid lubricants is 0.8 times or more and 2 times or less the total weight of the binder resin,
• a content of the graphite as the solid lubricant is 28% or more and 45% or less of a sum of the total weight of the solid lubricants and the total weight of the binder resin,
• an average particle diameter of the other solid lubricants is in a range of 0.1 μm or more and 5 μm or less, and
• the solid lubricating coating film has a film thickness of 10 μm or more and 150 μm or less.