| 摘要 |
A threaded coupling is configured of a pin (10) and a box (20). The pin (10) is provided, in order from the pipe main body of the pin (10) toward the distal end, with a male threaded part (11) and a lip part (12) including a seal surface (13), and the box (20) is provided with a female threaded part (21) corresponding to the male threaded part (11) of the pin (10), and a concave part (22) including a seal surface (23) corresponding to the lip part (12). The lip part (12) is provided, in order from the male threaded part (11) toward the distal end of the pin (10), with a neck part (14) and a sealing head part (15) including the seal surface (13), and the maximum outside diameter (D |
