THREADED JOINT FOR STEEL PIPES Russian patent published in 2020 - IPC F16L15/04 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to threaded joint for steel pipes. Thread (1) for steel pipes includes nipple (10) including external thread section (11) on outer periphery, and coupling (20), including, on inner periphery, section (21) of internal thread, made with possibility of being screwed on nipple (10). Section (11) of external thread comprises main external thread (111) and auxiliary external thread (112). Main external thread (111) is formed by a trapezoidal thread having constant width of the thread top and constant width of the thread recess. Auxiliary outer thread (112) is located in thread recess of main external thread (111) and has thread top width and thread top height that are smaller than top width and top height of thread pitch (111). In section containing pipe axis of nipple (10), angle of thread profile of insert side (111c) of main external thread (111) and angle of profile of thread of support side (112d) of auxiliary external thread (112) in adjacent places is more than 0 degrees.

EFFECT: invention can provide a certain resistance to torque and reduce production costs.

1 cl, 5 dwg