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• Application Range

It is suitable for drilling in where rock formation is overburden and need casing tube to support

• Outstanding Advantages

Simple structure,simple operation,reliable quality,retrievable drilling tools, and long service life.

• Different structures

Concentric system with ring bits, with wings and with blocks.

• Operation Procedure
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• 1. When the drilling starts, the wings swing out, and reams to drive the casing shoes and tubes into the hole.
• 2. When finished the drilling in overburden rock formations, reverse the drilling tools and the wings will get closed, and the drilling tools can be raised from the hole.
• 3. Next construction can be followed.