Kelly bars are key components in the execution of boreholes with hydraulic rotary drilling rigs. They transfer the torque of the rotary drive and the crowd pressure of the crowd system concurrently to the drilling tool. 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.

• 2 to 5 telescopic sections for depths of 15  - 100 m
• Torque transfer from 120 - 480 kNm
• Fully lockable Kelly bar (standard for all BG machines)
• Friction Kelly bar for drill attachments
• 6 drive keys with large lock recesses
• Shock absorbing system by spring assembly
• Standardized square Kelly drive stub for all drilling tools
• Noise damping system (optional)