Production Process of Unidrill Kelly Bar

Kelly bar is the key components in the execution of boreholes by hydraulic rotary drilling rigs.

A Kelly bar consists of 2 - 5 telescopic tubular sections with a system of drive keys and lock recesses, welded onto their outer surfaces.

Standard Kelly bars are fabricated with a total of 6 drive keys on each section. The tubular Kelly sections are manufactured from high-tensile steel to ensure minimum weight at adequate strength.

Unidrill is a highly specialized manufacturer of telescopic kelly bars to be applied to any brand and model of piling rig available in the market, especially used for BAUER, SOILMEC etc.

Here is the structure of a kelly bar:

The production process of Unidrill kelly bar include 9 main steps as below:

Step 1-The 1st tube straightness and roundness checking, adjusting

Step 2: Connecting and welding the tubes, Full Digital Ultrasonic Flaw Detector

Step 3: The 2nd tube straightness and roundness checking and adjusting

Step 4: Gib positioning and initial welding

Step 5: Kelly box connecting

Step 6: Mechanical automation welding robot

Step 7: Assistant welding

Step 8: The 3rd tube straightness and roundness checking and adjusting

Step 9: Assemble and painting

Bright point of Unidrill kelly bar:

- More craftman welding performed by highly-skilled workers

- Quality materials and stict workmanship guaranteed with one year warranty policy

- The largest kelly bar made by Unidrill

- Standardized : machinery and tooling for heat treatment, alignment and auto-welding

- Tube using-life prolonged system

- Upper shock absorber  with rubber or spring (where applicable)

- Lower shock absorber  with spiral/discs spring or rubber (where applicable)

- With reasonable gap between each tube to reduce noise be the best level.

Morevoer, all kelly bars can be provided of a damping noise system, which can sensibibly reduce the high frequency noises during the working operations. This system is composed by a phonoassorbent  material applied to the outer scope of kelly bar and protected by a steel plate.

We not only manufacture the high quality kelly bars, but also we provide the Technicial and Method solutions and guidance for bore pile engineering by our engineering team who has been in this field for more than 10 years.

For more details about Kelly Bar Design and Construction, please click here.