TREADED MEMBER FOR PIPE THREADED CONNECTION WITH HIGH FATIGUE LIMIT

摘要

FIELD: pipe threaded connections.;SUBSTANCE: part threads of the threaded member has a spiral groove coming out to the crest of a thread. The groove is made is made in all or a part of threads of one or both end zones, in particular, zone of the first catch threads and the zone of the last catch threads, and probably in the threads of the zone of the middle threads. The parameters of the groove are such that they allow reduce the hardness of the threads with the groove of the terminal zone or zones as compared with the hardness of the threads of the zone of the middle threads.;EFFECT: the pipe threaded connection obtained by screwing in of the threaded member with the conjugated threaded member possesses considerably high tolerance to the cylcic stresses of axial tension and/or axial compression or bending.;17 cl, 13 dwg