Kelly
Description
Kelly is a kind of  drill rod in the shape of a six-sided square cross section. It is made of AISI  4145H alloy steel in accordance with the specification of API and SY/ T 6509  standard. The raw material is conducted integrate heat treatment to achieve the  excellent thermal performance. With concern to its thread, it is treated with  cold rolling, copper plating and phosphating. 
Kelly is at the  top of the drill string, performing the function of drive. In the rotary table  drilling rig, kelly can cooperate with the kelly bushing and rotary table to  transfer the rotary torque to the drill rod and the drill rod in return makes  the drill bit rotate. Meanwhile, the kelly should also bear the hanging weight  of the drill string.

- HCX-13 Derrick for Geological Exploration1. The derrick has a reasonable structure with its story height of 1.3m. Thanks   to the light weight, it is easy to install quickly. 
2. It enjoys a high payload capacity. It can lift up the drilling rig drilling vertical hole at the height of 800m or inclined hole at the height of 600m in geological exploration... 






  