| 摘要 |
The invention relates to a threaded joint for steel pipes, formed on a pin (1) and a box (2), having a contact surface which includes a threaded part (3) and a non-threaded metal contact part (4) capable of stably providing gripping resistance and gas tightness, without a complex consistent ointment being applied, wherein a solid lubricating film formed with lubricating powder (for example molybdenum disulphide) and organic or inorganic binder, is formed on the contact surface of at least one of the said pin (1) and the said box (2), the ratio of the area occupied by the secondary particles, of 15 up to 60 mium, at an equivalent diameter of the equivalent area of the lubricating powder in the cross-section of the lubricating film, in the thickness direction, being of 5 up to 90%, and a fibre-like filling material (such as a bundle of yarns of inorganic substance), besides the lubricating powder, is admixed in the mentioned solid lubricating film, at a mass ratio, between the fiber-type filling material and the said binder, which is 0.01 up to 0.5, whereby the resistance to gripping, at high temperature, may be enhanced. |
