| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrence of galling in the vicinity a groove of a screw joint for steel pipe while assuring sufficient torque performance and sufficient seal performance.SOLUTION: A screw joint for steel pipe is constituted of a pin 1 and a box 2 each of which has non-threaded metal parts 17, 27 having non-contact parts 18, 28 where the pin 1 and the box 2 are not brought into contact with each other, and it includes a groove communicating with an internal space of the screw joint for steel pipe from the non-contact parts 18, 28 via a boundary surface between the pin 1 and the box 2 in the non-threaded metal contact parts 17, 27. An angle &thetas; formed by the groove and a contact surface at the non-threaded metal contact parts 17, 27 in the peripheral direction cross section of the screw joint for steel pipe is within 3° in at least the rear side of the pin 1 in a screw fastening direction. |
