Kelly

Kelly (Square/Hexagonal Drill Pipe) is the topmost component of the drill string, connecting the swivel to the drill pipe column. Its square or hexagonal cross-section engages with the rotary table bushing to transmit surface torque to the downhole assembly, driving the bit to fracture formations

Key Features

  1. 1.

    High-Strength Material

    • •

      Forged from AISI 4145H modified alloy steel, quenched and tempered to 285-341 BHN, with tensile strength ≥862 MPa and 3x higher torsional resistance than standard drill pipe


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  2. 2.

    Thread Design

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      Upper Box: Left-hand threads (LH) prevent unthreading during right-hand rotation;

    • •

      Lower Pin: Right-hand threads (RH) ensure tightening under rotation


  3. 3.

    Precision Manufacturing

    • •

      Drive flats milled to API Spec 7-1 tolerances (±0.1mm), with 100% ultrasonic testing for integrity

Kelly