| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a screw joint for suppressing the generation of galling at the time of repetitious fastening and unfastening, without using compound grease, having a low friction coefficient in fastening, and obtaining a high sealing property by low fastening torque. SOLUTION: A phosphate chemically treated coat 9 of a surface roughness Rmax of 5-20μm is formed on the surface of at least any one side nonthreaded metal contact part of a pin 2 and a box, and moreover the lubricating coat 6 of an inorganic macromolecular compound having a skelton of Ti-O, wherein the solid particulates having a mean particulate diameter of 0.005-3μm are dispersedly mixed at a rate of 3-60 wt.%, is formed on the surface of the coat 9. Otherwise, the lubricating coat 6 of resin, wherein the solid particulates of a mean particulate diameter of 0.005-0.4μm are dispersedly mixed at the rate of 5-70 wt.%, is formed on the surface of the coat 9.</p> |
