THREADED THREADED SEAL AND THREADED SEAL WITH EXCELLENT FATIGUE RESISTANCE

摘要

The invention relates to a stepped threaded joint and sectioned threaded joint having excellent resistance to fatigue, this threaded joint having to undergo a fluctuating load. /P P The thread 20, the threads 19, 20 of this joint, which must undergo the tensile load has a contact surface entrenched on the crests of the threads and whose contact height L is less than for the other part. As a result, the bending moment per maximum unit area generated in the thread bottoms f1 -f1 0 is uniform and the bending moment per unit area of the ridge is reduced. /P P Application to the screwed parts of accumulators or cylinders.