18 July 2017
Metal debris lost in a hole. Junk may be a lost bit, pieces of a bit, milled pieces of pipe, wrenches, or any relatively small object […]
18 July 2017
The heavy steel member, three-, four-, six-, or eight- sided, suspended from the swivel through the rotary table and connected to the topmost joint of drill […]
18 July 2017
Special device that, when fitted into the master bushing, transmits torque to the kelly and simultaneously permits vertical movement of the kelly to make hole. It […]
18 July 2017
A pneumatically operated device mounted on top of the kelly that, when actuated, causes the kelly to turn or spin. It is useful when the kelly […]