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How to Assemble Cone and Thread Fittings


In this step-by-step instructional video, learn how to properly assemble and install Swagelok® cone and thread fittings for medium- and high-pressure fluid system applications. These fittings are designed to provide dependable, leak-tight performance in demanding environments where reliability and safety are critical. An experienced technician will guide you through the complete process, including preparing the tube end, creating the cone and threads, inspecting the finished tube for an acceptable surface finish, and correctly assembling the fitting components. You'll also learn key installation tips that can help improve assembly consistency and reduce the potential for rework. When installed correctly, cone and thread fittings deliver reliable medium- and high-pressure performance across a wide range of industrial, energy, and testing applications. Additional information is available in the cone and thread fittings product catalog and the Type of Tube Fittings: Key Differences resource. 

 

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Video Transcript


In this video, you will learn how to assemble Swagelok cone and thread fittings with a Swagelok coning and threading tool.

You will need these components, available for 1/4, 3/8, and 9/16 in. tubing: manual adapter, benchtop vise, coning gauge, coning tool, threading tool, deburring tool, and chip brush.

To protect yourself from injury, be sure to wear safety glasses.

Attach the manual adapter to the bench vise. Insert the tube into the vise. The tube should slide freely. If it does not, loosen the bench vise slightly. One end of the tube should extend approximately 2 in. (50 mm) from the manual adapter.

Attach the coning tool to the tubing. Place the tip of the appropriate-sized coning gauge between the manual adapter and the end of the coning tool. Slowly slide the coning tool toward the gauge, using it to push the tubing, until the tool contacts the gauge. This establishes the proper gap.

Tighten the bench vise to secure the tube and verify the gap with the coning gauge. Apply cutting fluid as shown.

Engage the drive nut into the manual adapter and advance it until the coning blade contacts the tube. Loosen the drive nut 1/8 turn to back the blade away. Do not place hands near the coning blade while operating the tool.

Turn the coning tool handle clockwise for several revolutions at a constant speed while slowly advancing the drive nut. Stop frequently to apply cutting fluid. Provide gentle resistance to prevent the blade from biting into the tube. Continue until the tool bottoms out against the manual adapter.

While continuing to turn the handle clockwise, slowly loosen the drive nut counterclockwise until the blade is clear of the cone, then stop. If the tubing is not fully coned, repeat the process without moving the tube.

Remove the tube from the coning tool. Remove chips and, if necessary, lightly deburr the tube to break the burr. Do not chamfer the inside diameter.

Next, thread the tubing. Reposition the tube so it extends approximately 2 in. (50 mm) from the vise and tighten securely.

Slide the threading tool onto the tube until the die contacts the end. Apply cutting fluid through the chip window. Position the tool so the groove faces up to establish a starting point.

Begin threading by applying pressure and rotating the handle counterclockwise to cut a left-hand thread. Advance two full turns, then reverse 1/4 to 1/2 turn to break chips. Continue this pattern, applying cutting fluid regularly, until the proper thread length is reached.

Remove the threading tool by rotating it clockwise. Use care to avoid damage from trapped chips. Remove the tube and clean out any chips using a chip brush.

Inspect the tubing to ensure it is free of burrs, gouges, and scratches. Any mark that can be felt with a fingernail is not acceptable.

Place the fitting into the vise. Thread the collar counterclockwise onto the tubing until 1 to 2 threads are exposed at the cone end. Slide the gland nut onto the tubing and insert the assembly into the fitting body, ensuring the cone seats firmly.

Tighten to the appropriate torque values for medium- or high-pressure fittings.

Once inspected, install the assembly into your system following standard fluid system installation procedures. Contact your authorized Swagelok sales and service center for further assistance.