Externally Tensioned Hydraulic Nut

The Externally Tensioned Hydraulic Nut design provides seamless transition from torqued hardware to tensioned hardware. Until now, it has not been possible to replace torqued hardware with tensioned hardware unless there was a significant amount of thread protruding above the nut. Historically, retrofit has been accomplished by replacing the studs. However, with the application of our hydraulic nut, this is no longer the case.

The Externally Tensioned Hydraulic Nut is the perfect tensioning solution in applications in which there are no exposed threads above the existing nut. The standard hydraulic nut design fits inside the clearance envelope of ANSI standard heavy hex nuts resulting in a reduction of flange contact stress. It replaces the existing nut no matter the configuration.

Externally Tensioned Hydraulic Nut Overview

  • Retrofitting Capabilities
    • Change from Torquing to Tensioning without replacing studs
    • Radial footprint no larger than that of existing nut
    • Replaces any existing nut (i.e. hex, 12 point, cap, etc.)
  • Simple Installation
    • One-person installation and removal
  • No Extended Stud Thread Required
    • Utilizes the OD of the nut for tensioner gripping surface
  • Material Substitution
    • Nut material can be optimized for higher loads or temperature concerns


If the application requires a smaller envelope or even higher loads in the stud, there are several custom options available. These custom options include the use of a washer under the nut to better distribute the load and higher strength materials to withstand greater preloads while remaining in the existing nut’s radial footprint.

Download the  Externally Tensioned Hydraulic Nut Data Sheet

In addition to Torque and Nut Replacements, we also provide:

To learn more about our Externally Tensioned Hydraulic Nut, please contact a member of our team. We are happy to assist you with your project needs.

Externally Tensioned Hydraulic Nut Contact Us

Custom Engineering

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