HOCH GASDICHTE SCHRAUBVERBINDUNG FUER OEL- UND GAS-BOHRLOCHROHRE

摘要

A fluid tight threaded joint for oil or gas well pipes comprises a box (1) having an internal female thread and a pin (2) having an external male thread, the box (1) and pin (2) being screwed together in use. The external male thread on the pin starts from the pin end as a rounded triangular thread (3) and become a buttress thread (4) and the internal female thread on the box (1) is formed in a corresponding manner, thus forming a composite thread in a single thread train in each of the box and the pin, whereby a threaded joint with excellent sealing and repeat make-up performance is obtained.