5-element combined kelly bar

Ability to manufacture friction, interlocking and combined Kelly bar, and customize tubes series for Kelly bars on demand of customers
Advanced processing equipment and tooling facilities to ensure the high wear resistance and high reliability of Kelly bar
Selection of steel tubes and keys for power head manufactured by domestically renowned steel mills and adoption of special heat treatments process to reduce the weight of Kelly bar as a whole while guarantee the strength of Kelly bar  
Complete type spectrum and flexible designing and manufacturing capacities to ensure that Kelly bars are perfectly suited for the demand of customers.

Normally it is of 5 elements, in which the inner element is frictional characterized and the others are interlocking. It is mainly used in the project of deep drilling depth (out of the nominal drilling depth of interlocking Kelly bar) and hard soil condition (the efficiency is very low by using frictional Kelly bar).