Failure analysis and solution studies on drill pipe thread gluing at the exit side of horizontal directional drilling.

Highlights: [•] Revealed that bending moment is the cause of thread gluing at the HDD exit side. [•] A 3D drill pipe thread FEM model was established which could load combining loads. [•] Put forward some improvement measures and successfully used in HDD. [•] Proposed the beveled shoulder thread which could strongly withstand bending load. [ABSTRACT FROM AUTHOR]