Kelly, on the top of drill stem, shall be either Square or Hexagonal. In rotary table drilling, while drilling Kelly fits Kelly bushing and rotary table bushing and pass the torque of table to drill pipe to lead the drill bit rotation; and bear the weight of drill string. In the turbines and screw drilling, Kelly withstands weight of drill string and anti-torque suspension.
We manufacture Square Kelly and Hexagonal Kelly according to API SPEC7-1 and customer’s requirement, the materials used are forged or rolled AISI 4142H-4145H, and applied heat treatment craftwork such as quenching and tempering on the overall length. After this heat treatment craftwork, the HB will reach 285-341, Charpy impact ≥54J, also the craftwork made can ensure eccentricity of bore reach standard minimum wall thickness. The process for manufacturing Kelly is according to API Specification.
