摘要 |
<p>A tubular threaded joint is constituted by a pin and a box each having a contact surface comprising an unthreaded metal contact portion including a seal portion and a shoulder portion and a threaded portion. Of the contact surface of at least one of the pin and the box, the surfaces of the seal portion and the shoulder portion has a first lubricating coating in the form of a solid lubricating coating, and the surface of the threaded portion or the entire surface of the contact surface has a second lubricating coating selected from a viscous liquid lubricating coating and a solid lubricating coating. The first lubricating coating has a coefficient of friction which is higher than that of the second lubricating coating, and the second lubricating coating is positioned on top in a portion where both the first lubricating coating and the second lubricating coating are present.</p> |