Coning & Threading of High-Pressure Tubing

In medium- and high-pressure systems, coned and threaded tubing connections ensure safety and reliability.

Tools Required

  • Bottle of cutting oil
  • Collet
  • Collet wrench
  • Coning blades (and spare)
  • Coning tool
  • Deburring tool
  • Threading tool 
  • Tube holder
  •  Optional Complete Coning and Threading Kit includes everything you need!

How to Change the Coning Blades in the Coning Tool

To begin, the coning blades need to be properly installed in the coning tool. Locate the part numbers etched on one side of the blade and place the blade in the coning tool with the numbers facing outward. Once the blade is correctly installed, tighten the set screws on either side of the tool to secure the blade in place


Now that the tool has been prepped, the following steps will guide you through the coning and threading process:

  1. Insert the tube into the tube holder until it can be seen at the top of the viewing window.
  2. Place the flat end of the tube holder into a vice and tighten the collet nut to secure it in place.
  3. Cover the coning blades in cutting oil and install the coning tool onto the side of the tube holder opposite the tube by turning the knurled nut.
  4. Begin rapidly turning the handle of the coning tool while gradually turning the knurled nut to drive the blades into the cone on the end of the tube.
  5. Remove the coning tool by loosening the knurled nut.
  6. Loosen the collet nut and move the tube further into the tube holder and tighten it to allow you to hold the tube during the threading process.
  7. To start the first thread, install the die holder onto the end of the tube and firmly press down.
  8. Add cutting oil into the die holder.
  9. To obtain the appropriate amount of thread for a ¼” tube, turn the die holder approximately 12 times.
  10. Every few turns, reverse the die holder to break off any chips.
  11. The tube now has a cone and left-hand thread and can be removed from the die holder and the tube holder.
  12. Install the gland and collar on the tube with 1 to 2 threads visible above the collar.
  13. Lubricate the threads on the gland to prevent them from galling when the stainless parts are joined. 
  14. Install the tube into the fitting by hand tightening it.
  15. Place the assembly into the vice to torque the fitting using the appropriate sized torque wrench for your tubing.

MAXPRO Field Services, Installation, & Repair

Since 1995, MAXPRO Technologies has provided industry-leading high-pressure solutions. With a team of highly qualified engineers and technicians, we install every piece of equipment sold to ensure accuracy and optimal performance. We provide support for our products throughout their life cycle and offer field and in-house repair to allow customers to get the most out of their purchase. To learn more about our coning and threading services and equipment, contact us today.