Drilling Drag Type (DDT)

An Underreamer with exceptional expansion ratio for extended applications.



The HOC Drilling Drag Type Underreamer is designed to have a larger expansion ratio for milder applications that require circulation through the tool.

Features and Benefits:

  • Designed with the piston and actuator as a single component.
  • The tool operates with minimal moving parts.
  • Cutters actuate in a scissor motion.
  • Hydraulically expandable with pump pressure.
  • Reverse jetting actuation assures a full gauge hole and increased cutter cleaning and life.
  • The DDT is designed to utilize PDC or HOC’s ADD cutters.


DDT Specifications


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