| 摘要 |
PROBLEM TO BE SOLVED: To provide a screw joint for an oil well pipe, which is so excellent in a seizure resistance as is easy for an industrial manufacture, because an axial contact reaction occurs on a pin end side by fastening a screw joint so that a seizure is easily invited.SOLUTION: It is found that a contact reaction of a pin tube end side screw portion at the screw joint fastening time can be reduced by making a pin screw chamfer length proper. The invention provides a screw joint for an oil well pipe excellent in an anti-seizure, which is characterized in that an anti-screw pitch p ratio L/p of a pin screw chamfer length L is set at 1.0 to 3.0 in a premium joint. |
