| 摘要 |
PROBLEM TO BE SOLVED: To provide an oil well pipe screw joint of superior anti-seizure in which a screw seizure is hardly generated even if lubricant agent not including any high ductility substance component such as lead or copper and the like is used for fastening the screw joint.SOLUTION: A joint is comprised of a male pin 1 and a female box 2 that are connected in thread by male and female tapered screws. The locations where these both members are faced to each other have a screw part 3, nose portions 4 connected in series at the extremity end of the screw part 3 and a shoulder part 5 at the end of each of the nose portions 4. The nose portions have seal portions 8 to cause the pin and the box to be metal contacted in a radial direction. The screw part has a surface contact region 6 between the male thread trough surface and the female thread crest where a thread interference amount is positive. Either one of or both of the pin 1 and the box 2 in the surface contact region 6 are applied as surfaces to be formed with one or a plurality of grooves 7 storing lubricant agent. |
