FIELD: machine building.
SUBSTANCE: group of inventions relates to threaded joint. Surrounding element for tubular work column for hydrocarbons production subjected to dynamic bending stress contains cone female thread to interact with male thread to create rigid mutual connection of the tubular elements. Free end and female sealing surface are located between the free end and male thread. The female sealing surface is intended for entering in contact under screwed state with the male sealing surface to create metal-metal seal. There is ring groove located between the free end and female sealing surface providing axial distance exceeding zero, between the free end and transition area outside the female sealing surface, and radial distance that exceeds zero between the female sealing surface and chamfered edge of the free end. The groove has border created by the chamfered edge and border created by part of the transition area to protect the female sealing surface prior to connection by screw in.
EFFECT: invention improves reliability of the connection.
17 cl, 5 dwg
