A threaded joint for steel pipes constituted by a pin having male threads and a box having female threads is improved with respect to ease of insertion of the pin and galling resistance of the threaded portions. The stabbing flanks of the threads in a complete thread portion of one of the pin and a box has a two-step stabbing shape having a chamfer. The two-step stabbing shape has a stabbing flank angle α of 5-45° and a chamfer angle &bgr; of 20-60°. The ratio h/H of the chamfer height h to the thread height H of the pin is 0.25-0.50, or the ratio of the cross-sectional area of the chamfered portion to the overall cross-sectional area of the stabbing flank is made at least a value corresponding to a chamfer height ratio h/H of 0.25 and at most a value corresponding to a chamfer height ratio of 0.50.
申请公布号
EP2129952(A1)
申请公布日期
2009.12.09
申请号
EP20080740067
申请日期
2008.04.02
申请人
SUMITOMO METAL INDUSTRIES, LTD.;VALLOUREC MANNESMANN OIL & GAS FRANCE